Apparently there is a new pet but, I was noticing it yesterday, and it was on my Lock also, so its probably any pet class. Sometimes when you summon your pet, change zones, etc, you pet bar will disappear. I didn't have the problem with the pet just standing there, but I wasn't in pvp and had it on assist. My bar shows up but no buttons, dismiss and resummon worked, or /reload unless it'll cause you die. I thought it might just be my UI, but then today I saw an article on Outdps about it too. 
Conversation in Blizz development room, empty beer cans strewn around the floor.
"Hmm, hunter petsh don't die sho much on dishmountsh now… hic! Ain't that making 'em a bit OP?"
"You know wha'… hic!? You're right! What sha' we do?"
"How 'bout we make deir petsh… hic! jusht run off shometimesh… to catch a rabbit or shummat?"
"Nah, dat'd be too obvioush. Hey, who drunk all my beer?"
"You did, ya muppet."
"Oh yeah."
"Sho… what about we dishable deir pet bar, make 'em loshe control of deir petsh shometimesh?"
"Yeah, great!… but let'sh do it to all petsh… hic!, or dem hunter peshtsh might shtart moanin' again."
"Good idea! You get codin', mate. I'll go get ush shome more brain juishe."
Tap tap tap tap tap… hic!
(Disclaimer: this is in no way meant to represent what actually goes on in the Blizzard development team. It is rather a comment on the utter randomness of life, no matter what world we live in!)
^^^ Good stuff there Fel, I lol'd
I noticed that this morning - I thought it was because I downloaded Tidy Plates and didn't have something setup right.
Felinin - love it 
Love it Felinin 
You may not be too far off either.
Felinin said:
…
"How 'bout we make deir petsh… hic! jusht run off shometimesh… to catch a rabbit or shummat?"
…
Looks like they forgot they already did this to foxes. 🙂 (Good stuff Fel!)
Anyway, I’ve been experiencing an Eagle Eye bug. Whenever I cast it to the Magma Springs and Igneous Depths areas, I would sometimes disconnect.
Anj said:
Felinin said:
…
"How 'bout we make deir petsh… hic! jusht run off shometimesh… to catch a rabbit or shummat?"
…
Looks like they forgot they already did this to foxes. 🙂 (Good stuff Fel!)
Not just foxes my friend, my pets who are always on defensive will randomly run off and attack a target way out of my shot range. No idea how they target it them, but they do! And I hates foxes (I believe they should have been cunning, not ferocity… and coyotes too, for that matter! I'd love to have a coyote named Wile E. Coyote!) so I don't have me any.
Cheers
D
I've been seeing my pet run off when it or me gets hit with AoE spell. The best example is the behemoths in Molten Front, they'll hit random players with no attack toward them. I've been hit several times with their fire ball, and not had the black warning appear under my feet. When it happens, off goes my pet as soon as we've finished the mob we were attacking. This is in assist stance, and I've seen it on my lock too, so its not just hunter pets.
I hadn't played in some time, but I got for a bit last night and noticed this problem myself. It's quite annoying, but a quick dismiss/summon fixes it quickly.
I hardly ever look at my Pet Bar, as I have most of the actions macroed and keybound. Just the occasional click on Growl when changing activities, or an even rarer click on Cower.
So usually the first I know about this is when I tell my pet to attack (using a macro) and he just stands there next to me and says "Nah... don't think I will".
So it seems the PetBar bug actually disables the /petattack macro command too.