I run WordPress on an internal server (SunFire 280R, Solaris 5.8) with the following software versions from phpino:
PHP Version 5.1.0RC1
Apache/1.3.27 (Unix) ApacheJServ/1.1 PHP/5.1.0RC1
mysql Client API version 4.1.14
Before the upgrade (from 2.0.2 to 2.2.2) my colleagues were able to upload files using Admin/Manage/Uploads but they needed to use the WP-Stats plugin. This didn't work with that version of WordPress so I upgraded to WP 2.2.2. Stats worked, as did everything else except the Upload files. I've since upgraded to 2.2.3 and now to 2.3 and this issue is not fixed.
Clicking on the Upload link gives me a blank page in the latest Firefox on the Mac, on Safari3.x on the Mac I get "Safari can’t open the page “http://blog.cancerresearchuk.org/scienceupdate2/wp-admin/upload.php” because the server unexpectedly dropped the connection, which sometimes occurs when the server is busy. You might be able to open the page later." and "the page cannot be displayed . The page you are looking for is currently unavailable. The Web site might be experiencing technical difficulties, or you may need to adjust your browser settings." in IE on Windows. There is no problem with my webserver. All other pages are being served properly and all other functions are working in WordPress.
installed WordPress on my Mac using the same WP source. I can upload.
used the source files on the server above on my Mac, I can upload
Created a new instance of WordPress with a new table prefix on my server, upload gives the same errors above.
If I insert a phpinfo (); line into wp-admin/upload.php I get the PHP info displayed. The location of this line in the file affects how much info is displayed eg. if I enter it after "if (!current_user_can('upload_files'))..." i see info until "PHP License" but then it stops and nothing else is displayed. If phpinfo(); is entered after "require_once('admin.php');" the last section of PHP info is PHP Variables.
Can anyone shed any light on why things aren't working or offer any suggestions on where to look for where things are breaking?