Interesting (honest) !! So I normally watch TV series on my to work in the morning and for quite a while I have not used my Bluetooth headphones.
So this morning, I thought, what the hell, they are charged, lets give them a go!
MISTAKE! big stylie. Connected them up and started to watch an MKV and the surface ran like a 3 legged dog. Playback was just not happening in shape or form.
Shut the Bluetooth headphone off, jacked in a wired set and hey presto, back to normal.
Tried it with music too, with the same problem. I remember this being a problem when I first tried this with my RT, and it appears it’s still not fixed :-|