I'm having a similar problem myself, only it won't log me in. I think my problem would be solved with this too, if my inability to log in wouldn't make it impossible for me to go online too
At least with earlier versions (just recently installed 3.8, which seems to be the root of the problem), I was laggy until I popped into MP and let the servers list load. Try that. I've heard it worked for other people too back in the day.