The question remains whether he is trying to upload to gallery (no size limit) or attaching a file to a post (that's where we hit the 145KB size limit).
If uploading to the gallery, the only other thing I can think of is perhaps a corrupt file...but you say it's with all your images, not just one. RO, as a test you may want to email one of us one of the pix that wont upload. If we can upload it, it will help us rule out the image itself as the problem. Then we can look at your browser and/ or vbulletin settings.