Has anyone mentioned bugs with vehicles yet? That's one thing that as massively frustrating in BGs and just around the world, to start around in a vehicle only to learn that it doesn't respond to anything. Sometimes on malygos I've landed on a dragon only to learn my and his player icon both gone, and my action bar as well, and other random vehicle bugs that appear to be caused by warlock pets.
EXTREMELY frustrating and all too common.
On the malygos non-response thing: We have a guild rule. Once on your dragon, you have to de-select malygos as a target then re-target him. This has always addressed the bugs some of our members experienced.
xperl caused some bugs earlier, I belive their recent updates have addressed these.
Bar Mod addons could also cause this. I use bartender, which has been reliably good on this issue though.