I have the gallery feature set up on my discussion board. It seems some users can upload photos fine, other cannot. When the upload does not work the text message is still posted, but all links to any photos are broken image links.
I have the php memory allocation set quite generously in my server php.ini so don't think it's that causing a problem.
Could this be a timeout issue or something else? Maybe if a user has a slow internet connection then it would take them a few minutes to upload a photo and hence it times out during the upload? Don't know.