KNOWN ISSUE: 2gb or more RAM This issue has been solved. Remaining issues are likely buffer issues (See below) So we don't get more varied threads here, Russ dug up a old post explaining the problem: http://www.driverheaven.net/general...released-beta-revision-3545b.html#post1168448 This affects ALL versions of windows. XP x86, however, is less likely. It is not guaranteed to happen, but is very likely with more than 2gb of ram. Problem: "The card's hardware does not recognize addresses above 2 GB (uses a 31 bit (=2GB) DMA mask or something like that), so if Windows happens to create the buffers below that 2 GB barrier than it will work, if not, it will not work." Symptoms: Scratchy sound Clicking/randomness No sound at all (Except from inputs, such as Mic) Solutions: The only known solution is to go down to 2gb. (If you only have scratchy - but all there - sound, increase the length of your buffers. KX tray -> settings -> setup buffers) Existing threads: http://www.driverheaven.net/bug-reports/177813-windows-7-3-gb-ram.html http://www.driverheaven.net/bug-reports/185108-no-sound-windows-7-x64-rc1.html http://www.driverheaven.net/bug-reports/187717-massive-distortion-stuttering.html http://www.driverheaven.net/bug-reports/177630-ct4780-vista-sp1-only-makes-noise.html Mentioned in release threads: http://www.driverheaven.net/general...er-vista-x64-windows-xp-x64-alpha-3546-a.html http://www.driverheaven.net/general...ver-vista-x64-windows-xp-x64-beta-3547-a.html http://www.driverheaven.net/general-discussion/187614-3548-released-beta-x86-x64-builds.html Mentioned in bug threads: http://www.driverheaven.net/bug-reports/182462-x64-3546-bugs-issues.html If anyone knows of any more relevant posts I can link to, post them. Solutions are what we need, so if you're a programmer, read over Eugene's post and see if you come up with anything. If you've found a workaround, please post it for verification (Once you're sure this is the problem you were experiencing) Other than that, please keep "Yes, this happens to me too", and other posts out of the thread so that it will be easy for E to review. If this could get stickied, it'd be great... Or a Known Issues thread put up.