Yep, same happens to me, but its more noticable on login for a minute or two. I figure it is unoptimized coding, but im no programmer. Would be nice to see this fixed.

I use a PC that is definitely no slouch as well.

Intel Core i7-720 2.66GHz Quad-Core Processor
6GB DDR3 RAM
Palit GTX460 Sonic Platinum