Second upload per "session" fails and some other oddities

I guess I have everything installed correctly, at the first glance everything's working fine:

• file upload works
• file browsing/listing works

But:

• the first upload doesn't appear in the filelist immediately - I have to manual refresh the view to see the file
• the second upload doesn't work at all - nothing's transferred to the webfm-directory. When refreshing the whole page (or navigating to another node) I receive the status messages for the processed actions: one "Upload success" (for the first upload I assume) and another "Invalid upload path"
• there are some oddities when working with subdirs - when I change to a subdirectory and press the refresh-button webfm takes me back to the webfm-rootdir (one time it was vice versa also - took me back from rootdir to subdir)

Leaving the "session", i.e. navigating to another node, and "restarting" webfm that way resets the behaviour, that is I can upload one more file.

I think I have configured everything correctly ... proof of concept is there - it works for the first upload.

• Permissions are 775/664 - gid = apache-group.
• Directory settings:
  • webfm-root = /webfm
  • webfm-ftp = /webfm-ftp
  • For the Drupal filesystem-setting I tried both, relative and absolute path for files dir - didn't change anything.
• Running Linux/Drupal 5.1/Apache 2.0.54/PHP 5.0.4/MySQL 4.1.13.

Well, something's really gone wrong. I hope you can point me to what causes such behaviour or anything that helps me get webfm running. It seems like a really cool and desired module and I'd like to see it working on my company's site.

Regards, Matze