Would you mind emailing me the DXDIAG output of your system?
1) Go to "Start" from the Windows desktop
2) Select "Run" from the pop up menu
3) In the Run dialog box, type DXDIAG and press
4) After a few seconds the DXDIAG utility will be ready
5) Press the "Save All Information" button
6) This will save the DXDIAG data to a file of your choice
7) Once you have done this, simply email the file to me and I can look for any issues your system might have.
This will be a good start, but there could also be interrupts being shared which could cause unstable connections. Let's start with DXDIAG and see if anything rears its head.