help with avatars and gallery

hi ive just relised in my site users can upload an avatar but it wont show up on profiles. also when a gallery pic is uploaded same problem occurs. the folders had been chmodded at 777 as in the settings sugested on installation

Check PHP settings
Should be enabled GD extension

but in downloads are screens?

nope theres nothing although the file is uploaded nothing appears and if i click the link i get 500 error