Cause you kept quitting with "SEND Q EXCEEDED", thus Venom banned you.
You were probally doing something like excessive /mode's or messaging or something, and it was just getting plain annoying (cause it IS annoying, starts to flood sometimes :/)
Anyways, you're unbanned.
(BUT, Apparently you were doing that crap for hours... so watch it, you'll get banned if you keep repeating it...)