User:McCormack/Upload problem

System messages
Warning: fopen(/var/tmp/phpepykKu) [function.fopen]: failed to open stream: No such file or directory in /usr/home/[account_name]/www/htdocs/en/includes/MacBinary.php on line 46

+ 3 further ones.

Actually this line probably isn't the main problem itself, as the macbinary check is optional, but the fopen's are failing everywhere else as well, when the reports are switched off.

Playing around with LocalSettings.php can produce more errors if required. If the upload form is checked to ignore warnings, the file actually uploads and is placed in the /images/... dirctory structure, but it cannot be displayed using the tag, so this is not a viable workaround.

Background

 * Upgraded from MediaWiki 1.6 to 1.11. Installation went fine, and there are no signs of any other problems - e.g. page creation, movement, file deletion, logins, etc all work fine.
 * Images uploaded fine before the upgrade. On Mediawiki installations on the same server which are still at 1.6, the file uploads still work fine.
 * All images previously uploaded (before the upgrade) work fine with the new MediaWiki installation.

Things tried so far

 * Set just about every directory permission in sight to 777.
 * Jiggled every available flag for LocalSettings.php
 * Trawled through php.ini and ensured that everything is as it should be.
 * Put debugging code into SpecialUpload.php and verified that Mediawiki 1.6 (working) was using the same upload directory as Mediawiki 1.11 (not working). The only difference between the two installations is that 1.6 is using PHP4 and 1.11 is using PHP5 (both on the same server). 1.11 uses an .htaccess entry to send php files to the php5 parser.
 * Trawled through this site and google for anything even resembling a similar problem.

Solution
? :)