I am having trouble changing my avatar. I removed my old one, and then uploaded the new one. My avatar became my old avatar sized up to the size of the new avatar I was trying to upload. I removed it now, after trying many times.

Usually images cache themselves. This reduces the time you spend loading pages you visit frequently.
Do this. Upload your new avatar.
When you see the new / old avatar, right click on image. Select the option that is similiar to "Copy link LOCATION". Paste that url in a new browser window. It should be something like www.staredit.net/uploads/avatars/96.jpg
Refresh that window until your new avatar pops up.
Go back to SEN and it should be fine.

Thanks, it worked.