Avvisad av servern - Rejected by server

Ohhh... This just drives my crazy! I have tried every day in three days now to upload some pictures! But it's just not possible! Every time I try it just say "Avvisad av servern" (Rejected by server) or "Säkerhetsfel" (Security error)! I don't know what's wrong but I will send a e-mail for Blogger now. If anyone else experienced the same thing and know how to solve this problem, please HELP!