When you have a dead pet and use the Norn Snow Leopard Elite (and probably the other transformations too) once you get out of the Elite the next time you swap your pet it will be summoned dead. That means 20 seconds of no pet for the ranger and 60 sec CD on pet swap if you are in fight.
The dead pet will even happen after one hour if you never switched your pet and as you can imagine having a dead pet in the middle of the fight is a real problem to the ranger.
This bug has been there for at least a year and I have reported it back then with screenshots. It is a pretty annoying bug.
I would be very thankful if you could fix this bug.
If you need more information feel free to PM me.