Why am I not allowed to post attachments?
In the posting rules I am allowed to do everything except post attachments.

 

...that's why. Get up to 50 posts and be a member for 30 days. Seems like you got the thirty days covered already.

If you must have something uploaded at once, just use photobucket.com or imageshack.com. You will need to create an account, which doesn't take long at all, and the rest is pretty gravy.