There is no problem with using VPN to access the forum.
I Didn't check bpip but doesn't look like your account got banned as the bitvest signature is still displayed in your signature space!
What is the message you get when you log in?
"Sorry nevsky, you are banned from using this forum! For security, your account has been locked. Email
locked...@bitcointalk.org" Yes, maybe the reason is in the signature campaign. Thank all for help guys!