I know the amount of frustration associated with slow gameplay, or your game pausing. I've had it for a while. If you're game is slow in general, or pauses for a little bit of time before resuming (like mine did) I might have a solution. Now obviously you should have a decent graphics card and RAM, if you have these problems, first make sure you've got that stuff.
If you still have this, I recommend buying a can of compressed air, and cleaning out the inside of your pc. Just turn off your pc, pop the case off, and spray the air inside, all over EVERYTHING. This did the trick for me and many others, hope I can help someone else...
Good luck with your troubles,
DA
ps...even if you dont have these problems, you should do this regurlarly. Some websites recommend every 4-6 months to keep your pc running at its peak.