Audio Glitches?!?!?!

I just got Cubase 6 not to long ago and Noticed all my audio has this distorted sound. Even the metronome click distorts. It gets less and less noticable with the buffer rate high, but that causes lantency. I can work normaly in Pro Tools at a buffer rate of 256 or 512 without any noises…Whats going on in cubase? I’m not even using any plug-ins…if I import a simple audio file it distorts. I have a Quad core amd processor and 6gigs of ram, I’m running on Wind7 64bit. Anybody know whats going on? I cant do anything audio related in Cubase. VSTs work find though with out any distortions…even when I run many huge vst’s like omnisphere,kontackt,Kore…ect