Are you seeing any error message at all? It will usually show on with a red or yellow background at the top of the thread or post.
I have found that I cannot add attachments using Internet Explorer (9.0.8112.16421). It goes through all the motions but there is no attachment on the newly created post. I tried the exact same procedure in FireFox (20.0.1) and it worked fine.
Log into access your profile, ask and answer questions, share ideas and more. Haven't signed up yet? Register
Start with some of our most frequented solutions to get help installing your software.