Cubase 5 noise on sound

Hi,

I’ve installed cubase 5 to win8 (64bit). I added vst instruments and also vocal effects. When I try to change the instrument on the same vst, I start to hear the sound with lots of noise. I don’t know why this happens because sometimes it doesn’t happen! (and it is not related to a specific vst instrument, same problem occurs on other vsts also)
To fix it, I enter to device properties on cubase and change my driver from m-audio fast track pro to asio4all and return back to m-audio driver. By doing this, it is somehow repaired. After a while same problem occurs again.

Does it related to cubase software or my sound card driver? (by the way I use the same sound card on another laptop which is win7 (32bit) and everything is ok)

How can I fix it?

Thanks