Neither 6.x-1.x-dev or 6.x-1.0-alpha5 work on a completely clean site.

Do you use the English locale on your website? If not, you encountered the issue fixed by http://cvs.drupal.org/viewvc/drupal/contributions/modules/comment_upload..., but the fix somehow did not propagate to the 6.x-1.x-dev archive.

BTW: None of the current archives (alphas and dev) are suitable for use on production sites.

I believe this fixes the problem.

--- comment_upload.broken/comment_upload.install        2010-01-04 15:41:07.903961271 -0600
+++ comment_upload/comment_upload.install       2009-02-01 14:06:40.000000000 -0600
@@ -235,7 +235,7 @@

   db_create_table($ret, 'comment_upload', $schema['comment_upload']);
   if (substr($db_url, 0, 5) == 'mysql') {
-    $max_file_id = db_result(db_query("SELECT MAX(fid) FROM files"));
+    $max_file_id = db_result(db_query("SELECT MAX(fid) FROM {files}"));
     $offset = $max_file_id + 1;
     db_query("INSERT INTO {files} (fid, uid, filename, filepath, filemime, filesize, status, timestamp) SELECT cuf.fid + %d, c.uid, cuf.filename, cuf.filepath, cuf.filemime, cuf.filesize, 1, c.timestamp FROM {comment_upload_files} cuf INNER JOIN {comments} c ON cuf.cid = c.cid", $offset);
     $max_file_id = db_result(db_query("SELECT MAX(fid) FROM {files}"));

I am new to Drupal and do not know exactly what I should do with your fix. I have the Comment upload 6.x-1.0-alpha5 installed in my modules folder. Is your "Fix" that I open comment_upload.install in a text editor and replace the line

$max_file_id = db_result(db_query("SELECT MAX(fid) FROM files"));

with the line

$max_file_id = db_result(db_query("SELECT MAX(fid) FROM {files}"));

Save the file, and then run update.php?

Since I already have Comment upload 6.x-1.0-alpha5 installed, do I need to do something else first?

I would like to know how to apply this fix correctly, so I do not create any other problems

Thanks for any assistance

I dont think that this is the problem.
it has to do be somewhere in the hook_comment process...

I fail to see how an update hook could cause trouble on a fresh install. (The update is broken though).

Is there actually any way to get comment upload to work? Things are getting very confusing. Latest dev (01.12-09) still does not fix the preview issue and when I try to go back to the last working version (cvs) the module completely gets disabled from the module page with an incompatibility warning for D6.15 (not tried with a fresh install yet).

Such a pitty... but somehow I start being afraid that after so much time we will never see a really usable version.

The module is essentially unmaintained. Netaustin, dww and I only care for it to work on Drupal.org itself.

Thanks a lot for the clear statement. At least I know now that we cannot expect quick fixes, although it is very sad to hear since this is a very helpful module. Well hopefully we will have a working version sometime in the future :)

6.x-1.x-dev appears to work fine on a clean test site. I think this was probably fixed via other commits.