I've been consistently finding blocks once per day with my Core 2 Quad 9400 OC'ed to 3.5GHz on the second windows client. My pps is usually around 2500, so I'm either very lucky or something is wrong on your end.
Which build are you using, HP5? If so, mind sharing your settings?
Check your PM. Need help asap
Now I got 3 blocks and PPS 20 30