Gallery module throwing configuration error

Changed this to a bug report. Some of my users intermittently get this message and a white screen:
Fatal error: Call to undefine d function: drupal_get_path() in /home/afana/public_html/drupal5/modules/gallery/gallery.module on line 4

Repeated refreshes and it eventually works and my site appears as it should. I can't predictably create it, it seems to occur at random. Upgrading to 5.x-2.1 did not help.

Upping the memory for Drupal to 50M made no difference; it was at 30M. Gallery is already at 50M.

The Drupal log has this which may be related:

Error in function '_gallery_init()' (gallery_base.inc:111):

    * Unable to initialize embedded Gallery. You need to configure your embedded Gallery.
      Error (ERROR_PERMISSION_DENIED) : Invalid return URL! The requested URL http://www.afana.com/drupal5/index.php?q=gallery&g2_view=core.UserAdmin&g2_subView=register.UserSelfRegistration&g2_return=%2Fdrupal%2Fv%2Fess_bris_r8_07%2Fess_bris_r8_07_149.JPG.html%3Fg2_0%3Dgallery&g2_returnName=photo tried to insert a redirection to /drupal/v/ess_bris_r8_07/ess_bris_r8_07_149.JPG.html?g2_0=gallery which is not a part of this Gallery.
          o in modules/core/classes/GalleryUrlGenerator.class at line 863 (gallerycoreapi::error)
          o in modules/rewrite/classes/parsers/modrewrite/ModRewriteUrlGenerator.class at line 42 (rewriteurlgenerator::initnavigation)
          o in init.inc at line 147 (modrewriteurlgenerator::initnavigation)
          o in modules/core/classes/GalleryEmbed.class at line 129
          o in /home/afana/public_html/drupal5/modules/gallery/gallery_base.inc at line 101 (galleryembed::init)
          o in /home/afana/public_html/drupal5/modules/gallery/gallery_base.inc at line 332
          o in /home/afana/public_html/drupal5/modules/gallery/gallery_menu/gallery_menu.module at line 37
          o in ??? at line 0
          o in /home/afana/public_html/drupal5/includes/module.inc at line 406
          o in /home/afana/public_html/drupal5/includes/menu.inc at line 1221
          o in /home/afana/public_html/drupal5/includes/menu.inc at line 220
          o in /home/afana/public_html/drupal5/includes/menu.inc at line 391
          o in /home/afana/public_html/drupal5/index.php at line 15

Yes, the link to the issue on Calendar module sounds very similar.

It does appear cache related somehow. I tried disabling caching. That didn't make the problem go away for me, however users in admin mode do not see the problem.

Here is the htaccess file for Gallery itself:

AddType application/x-httpd-php5 .php
# BEGIN Url Rewrite section
# (Automatically generated.  Do not edit this section)
<IfModule mod_rewrite.c>
    RewriteEngine On

    RewriteBase /gallery2/

    RewriteCond %{REQUEST_FILENAME} -f [OR]
    RewriteCond %{REQUEST_FILENAME} -d [OR]
    RewriteCond %{REQUEST_FILENAME} gallery\_remote2\.php
    RewriteCond %{REQUEST_FILENAME} !/gallery2/main\.php$
    RewriteRule .   -   [L]


    RewriteCond %{THE_REQUEST} \ /gallery2/v/([^?]+)(\?.|\ .)
    RewriteCond %{REQUEST_FILENAME} !/gallery2/main\.php$
    RewriteRule .   /gallery2/main.php?g2_view=core.ShowItem&g2_path=%1   [QSA,L]

</IfModule>

# END Url Rewrite section


php_value post_max_size 10M
php_value upload_max_filesize 10M
# php_value memory_limit 58388608

here is the one for Drupal:

# BEGIN Url Rewrite section
# (Automatically generated.  Do not edit this section)
<IfModule mod_rewrite.c>
    RewriteEngine On

    RewriteBase /drupal5/

    RewriteCond %{REQUEST_FILENAME} -f [OR]
    RewriteCond %{REQUEST_FILENAME} -d [OR]
    RewriteCond %{REQUEST_FILENAME} gallery\_remote2\.php
    RewriteCond %{REQUEST_URI} !/drupal5/index\.php$
    RewriteRule .   -   [L]


    RewriteCond %{THE_REQUEST} \ /drupal5/v/([^?]+)(\?.|\ .)
    RewriteCond %{REQUEST_URI} !/drupal5/index\.php$
    RewriteRule .   /drupal5/index.php?q=gallery&g2_view=core.ShowItem&g2_path=%1   [QSA,L]

</IfModule>

# END Url Rewrite section

# BEGIN Url Rewrite section
# (Automatically generated.  Do not edit this section)<IfModule mod_rewrite.c>    
RewriteEngine On    

RewriteBase /drupal5/    

RewriteCond %{REQUEST_FILENAME} -f [OR]    
RewriteCond %{REQUEST_FILENAME} -d [OR]    
RewriteCond %{REQUEST_FILENAME} gallery\_remote2\.php    
RewriteCond %{REQUEST_FILENAME} !/drupal5/index\.php$    
RewriteRule .   -   [L]    

RewriteCond %{THE_REQUEST} \ /drupal5/gallery/([^?]+)(\?.|\ .)    
RewriteCond %{REQUEST_FILENAME} !/drupal5/index\.php$    
RewriteRule .   /drupal5/index.php?q=gallery&g2_view=core.ShowItem&g2_path=%1   [QSA,L]

</IfModule>
# END Url Rewrite section#

# Apache/PHP/Drupal settings:
#

# Protect files and directories from prying eyes.
<Files ~ "(\.(inc|module|pl|sh|sql|theme|engine|xtmpl)|Entries|Repositories|Root|scripts|updates)$">
  Order deny,allow
  Deny from all
</Files>

# Set some options.
Options -Indexes
Options +FollowSymLinks

# Customized error messages.
ErrorDocument 404 /index.php

# Set the default handler.
DirectoryIndex index.php

php_value max_execution_time 360
# Override PHP settings. More exist in sites/default/settings.php, but
# the following cannot be changed at runtime. The first IfModule is
# for Apache 1.3, the second for Apache 2.
<IfModule mod_php4.c>
  php_value magic_quotes_gpc                0
  php_value register_globals                0
  php_value session.auto_start              0
  php_value upload_max_filesize           24000000
  php_value post_max_size                 24000000
  php_value max_input_time                360
  php_value file_uploads                    1
  php_value max_execution_time            480
  php_value memory_limit                  50000000


</IfModule>

<IfModule sapi_apache2.c>
  php_value magic_quotes_gpc                0
  php_value register_globals                0
  php_value session.auto_start              0
  php_value upload_max_filesize           24000000
  php_value post_max_size                 24000000
  php_value max_input_time                1200
  php_value file_uploads                    1
  php_value max_execution_time            360
  php_value memory_limit                  50000000





</IfModule>

# Reduce the time dynamically generated pages are cache-able.
<IfModule mod_expires.c>
  ExpiresByType text/html A1
</IfModule>

# Various rewrite rules.
<IfModule mod_rewrite.c>
  RewriteEngine on

  # Modify the RewriteBase if you are using Drupal in a subdirectory and
  # the rewrite rules are not working properly.
  #RewriteBase /drupal5

  # Rewrite old-style URLs of the form 'node.php?id=x'.
  #RewriteCond %{REQUEST_FILENAME} !-f
  #RewriteCond %{REQUEST_FILENAME} !-d
  #RewriteCond %{QUERY_STRING} ^id=([^&]+)$
  #RewriteRule node.php index.php?q=node/view/%1 [L]

  # Rewrite old-style URLs of the form 'module.php?mod=x'.
  #RewriteCond %{REQUEST_FILENAME} !-f
  #RewriteCond %{REQUEST_FILENAME} !-d
  #RewriteCond %{QUERY_STRING} ^mod=([^&]+)$
  #RewriteRule module.php index.php?q=%1 [L]

  # Rewrite current-style URLs of the form 'index.php?q=x'.
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]
</IfModule>

Does this give you any insight?

I disabled the gallery module for the moment because otherwise my site is unusable.