Bluetooth and Bose sound dock suddenly drops sound level

I posted this on the help section, but no one could help.

Bluetooth and Bose sound dock suddenly drops sound level
My IPad and my IPhone 3GS and connected to Bose Sound Dock suddenly drops sound level and then returns to normal.
Wifi is Apple Air Port Express. Music drops sound at random times, just very briefly about 3 times an hour. But it is annoying.
Both Apple phone support and Bose tell me they have the latest Bluetooth running on respective devices.
Could someone please help?