Help:64Bit cubase in Windows 7

A problem have bothered me for a long time :
When I moved mouse in cubase,there always a click noice appeared,if I work without mouse,there’s no crack,just be OK.This problem just be found on 64bit Cubase in Windows7,if I changed to 32bit Cubase or Windows Serve2008,everything is fine.
How can I fix it?

RME 9632
64bit windows7 professional sp1
64bit cubase6.0.2
AMD Phenom II X4 955
GIGABYTE GA-770TA-UD3
ATI RADEON HD 4850
8G DDR3 1600
Logitech MK520

Did you turned off Windows sound in Control Panel/Sounds and Audio Devices Properties/Sounds/Sound scheme: No Sounds

yes,I tryed to turn off all other soundcard,and close all powersave options ,like C1E K8 etc. but it’s just no help to solve this problem.

What kind of mouse? Try using generic Windows drivers for it. What brand of video card? Drivers up to date?

EDIT: I see Logitech in your sig. Probably the culprit. As stated, use the generic Windows driver.

Did you turn off Aero? I discovered that turning off visual effects actually moves the graphics processing from the GPU to the CPU causing pops and clicks. Especially with movement on the screen.

The graphics drivers may be the problem. Try the drivers from the CD that you got when you bought the card. If that doesn’t help also try installing the latest drivers from AMD/ATI. Also be sure to uninstall the current drivers first.