thanks for the information. I am not able to reproduce it, though 
with my MBP and the Deep Sleep Widget.

After my MBP wakes up, the Bluetooth icon first shows unavailability, 
but changes to available a second later.

So I did a bit research and stumbled over

http://andrewescobar.com/archive/ 2005/11/11/how-to-safe-sleep-your-mac/

and

http://discussions.apple.com/thread.jspa?messageID=4516751&tstart=0

where loads of people report about problems with safe sleep and 
Bluetooth. From what I can extract from it, this seems to be a 
problem with the menu extra that displays that icon as killing/ 
restarting the SystemUI server (which drives these menu extras but 
has no relation to Bluetooth at all as far as I can say) "solves" the 
problem. Bluetooth seems to work just fine even if the menu extra 
displays the wrong status.

The problem also doesn't seem to be consistent for those affected 
according to the latter link.

That said, I also wouldn't know how the Remote Buddy Kernel Extension 
could cause this as it does not contain any code that could hinder 
the kernel extension for the Bluetooth hardware in the MBP from loading.

Hope that helps.

Best regards, 
Felix