I believe Malcolmb is correct. it's most likely a driver problem.
Make sure you have the correct drivers for W7. Does the Behringer have its own drivers or does it use generic drivers provided by Windows? If you are using generic drivers, be sure to always start everything up in the same sequence. For some reason, non-device specific drivers seem to get easily misdirected. Also, be sure to start everything up before you open SHS6.
Have you updated the drivers for all of your other USB devices?
Open the Options>Audio dialogue. Make sure everything looks correct, and click OK.
This should re-establish communication between SHS and your interface. I've had to do this when I had a similar problem with the built-in Realtec. Sometimes it took 3 or 4 time before it settled down.
Running the Wave Profiler again may help. If you are using ASIO, you will need to switch to WDM first.
Try both WDM and ASIO drivers modes. While ASIO is generally considered to be best, I've seen reports of better performance with WDM in W7. This is system specific, so the only way to know for sure is to try it.
Re-installing SHS6 is probably overkill. You can delete the audio.ini file(in the Cakewalk programs folder).
The next time you start SHS6, it will build a new one.
That's about all I can think of. Hope it helps.