Yes, each time I upload a new test image, it is a new file that has not been used before.

It took me a while but I finally caught on to the random size being related to the image file size. I've looked everywhere I can think of and have not been able to find anything limiting the size so low.

OK, try this: in the adminCP go to Attachments > Attachment Permissions, and check to see if any custom permissions have been set for a user group (should show up in red).

Nothing is in red. Test pictures are being uploaded at completely random sizes regardless of their file size. I just uploaded one at the correct pixel size that has a file size of 94kb and right after that I uploaded an image that 95kb it is shown in much smaller dimensions. 1kb shouldn't make the image 50 pixels smaller. This is ridiculous and I'm ready to demand a refund from vBulletin.

--------------- Added [DATE]1323049924[/DATE] at [TIME]1323049924[/TIME] ---------------

EDIT:

It seems the issue has been solved by someone who sent a PM and may wish to remain nameless. In the admin control panel I turned off image the resizing option and then increased the allowable file size well past 1000000 in the attachment manager.

A very big thank you goes to this anonymous person who sent the PM and to kh99 for their help.

Oh right - I should have thought of turning off image resizing. Good work, whoever that was.

Anyway, glad you solved it.