I have found problems on my sorcerer with pet summoning since the patch. This can be awkward when soloing and finding yourself totally solo!
1) Pets do not always summon
2) pets do not always UNsummon
3) In either case, the tool bar icon does not glow indicating in use.
Sometimes, when there are no pets, the Character panel will show the pet-dependant buffs in play, and the pets may just pop into being at some time running around.