Parrot DS1120 speakers slient after Windows 7 sleep mode resume

Hello,

I have three sets of Parrot DS1120 speakers on different systems.  Two are for Windows Media Center PCs.  I am in the process of upgrading these systems to Windows 7 and attaching the Parrot speakers to them.  My situation is as follows:

Speakers work well while the system is running, after a clean boot, etc.
Once the system is put into sleep mode and then resumed the speakers go slient.  There are no errors on the Windows 7 system, the bluetooth device works fine according to the bluetooth control panel.  Just no sound comes out.

What I have tried:
Using the dongle instead of the onboard bluetooth controller
Disabling all onboard audio

Can you please help?
I will hopefully be able to test this on my Vista systems once they are unpacked in about a week's time.

Derek