Having issues with your pet bar not showing up when you dismount or when you call your pet? I’ve been hearing about this for some time now, and although it doesn’t happen to me much it does happen — and it is really annoying! But thankfully, it looks like Blizzard is making a concentrated effort to gather information about the problem as demonstrated by this post on the Bug Report forum.
In addition, there’s a useful post on the same forum about known issues in Patch 2.1.2. As of right now, the only hunter-specific thing I see in there is that Hunter’s Mark does not properly update itself when re-applied.
And finally, the Bug Report forum also has an interesting post on issues that are not bugs but that people keep trying to report anyway.