Yeah its still buggy at the moment. A few unusual things I experienced over the weekend:

1. Queued up, got instance ready message - click accept on toons, loading screen pops up, then drops me back to Dal with "additional instances can't be launched" and the DF debuff.

2. Random dungeon is Occulus (which I don't particularly like) so I port back out and figure I'd do the 1st 2 bosses of Drak'Tharon while I'm waiting for the DF debuff to expire. After the 15 mins are up I port back to Dal and fire up the DF - and I get Drak as my random dungeon - and port back into the exact same dungeon I left minutes ago (with trash cleared and 2 bosses down). I did get the extra emblems at the end though.

I'm sure this will get fixed over the coming weeks....

Cheers,
S.