Windows 7 - 16bit mono 48 khz audio does not work fine on Windows 7

I am facing a strange issue with Windows 7 RC on fresh installation. When I connect my Audio source which gives 16 bit 48 khz output to Windows 7 and try to use some application like graph edit to stream audio. The quality of the streamed audio is really bad. After this if I use Microsoft Office communicator and do the audio streaming, the audio improves a lot and am able to stream a good audio. This improvement is also audible with Graphedit if I use next. I suspect some filter are getting correctly aligned for audio after using MOC. Can somebody help me on this? should have some new filter installed for the 16 bit mono samples on Windows 7?

Would you please fill out your system specs in your user CP? This way everyone will know what hardware you are using and will help a great deal in finding the source of your trouble. Thanks and welcome to sevenforums. Fabe

My PC configuration is

Processor type: Intel Core 2 Quad,
Processor Speed , 2.2 GHZ,
RAM: 2 GB RAM
Video Driver : NVIDIA GeForce 9600 GT (Microsoft Corporation-WDDM v1.1)
N/w Driver : Intel ® 82566DC Gigabit network connection
Audio Driver
Driver name : High Definition Audio Device
Driver Provider : Microsoft
Driver Date: 7/13/2009
Driver Version: 6.1.7600.16385(win7_rtm.090713-1255)
Digital Signer: Microsoft

Try here, for a new driver, it might help you.

Realtek