My sound is "lagging"

This is an odd problem I have had for awhile. Out of the blue about 6-9 months ago, my sound started acting weird. Whenever I played music, games, anything that outputted audio, the sound I heard was slightly slowed down and actually started tripping over itself (it regularly alternated between slow and fast with there being good amount of noise each time it did this). I have reinstalled the WinXP OS without it affecting anything. The sound card (a Hercules XP card) doesn't appear to be the problem because after installed the OS, I listened through the mobo's audio out. I am running a MSI RS480M2-IL w/ 1.5 gigs RAM; so, it shouldn't be a hardware problem.

The only thing that I have found that remedies this problem is leaving the computer on for awhile. It doesn't matter if I put it into standby mode for a night or weekend, as long as it hasn't been turned off, the sound is fine. Anyone have any ideas what could be causing this?

freaking yes...this exactly thing happened to me today, and ive been trying to find answers, EVERY website, sound, sound computer from the computer is slow and trippy and it sounds soo evil like. Its weird. Any Inputs??

^ what speakers are you using? Also do you leave them plugged into the mains when the PC is off?

Im using my factory sony viao speakers, had this computer roughly 4 years now and this is the first time ive ever witness this at all. I rarely turn off my computer...