Cannot change my avatar, everytime I try to upload my favourite tux, website throws error: A server error occured, please try again later. I am trying this for whole week but still I think its not problem on my side. Help please :(

I'm trying to submit an avatar image when I edit my profile but it says my image is larger than 50kb, but the image is 20.8kb and 200 px x 200 px with 8 bit/pixel. Is there a way to work around this problem?