Reply to Serato lag and glitching! help!

I run win 7 64 bit, core 2 duo @2.16 with 4 gigs of ram.

If i dont term off my windows theme completely and cut back on all background processes drastically my serato waveforms and program glitches and is extremely laggy.

Once services and background programs are cut back 2 decks on serato runs smoothly but starts glitching and lagging badly again on 3 decks.

IMO my laptop is more than suitable to be running serato smoothly. Anyone have any idea what this issue could be?