Hi Peter,
I'll assume you know what you're doing and it's all been set up correctly.
The stand, on a BV7 at least, can do all kinds of internal damage if plugged into the TV whilst the set is switched on. Not sure if it's the same on the BV10 - but did you unplug and re-plug the stand whilst the TV was powered up?
Disconnecting and re-conecting MasterLink (if you have a housefull of B&O) with everything switched on can also cause older products to throw their rattle out of the pram. I always power everything down in the whole house, do the ML stuff, then switch it all back on at once. Serves me well and saves me time, assuming the owner has PIN codes!
My tip as a first option - If you can, go into the Service Menu and do a system reset to factory default. It sounds like your BV10 is getting it's knickers in a twist, as these are multiple (and it would seem unrelated) issues.
As a thought, did you select the speakers correctly in the menu? Did you do a speaker level test and see if they all hiss.
I wish i was there to have a cold beer and get to the bottom of it for you..
Lee
BeoWorld - Everything Bang & Olufsen