All the time pets (including zombies) are getting stuck and ignore commands, including rescue. I couldn't understand what causes that bug, but they seem to reset their behavior after any successful kill. So, if your pet ignores you, kill a turkey for instance, and it will listen you again. The worst here is that you never know if they'll listen you, initiate combat, order to rescue... and nothing happens.

Please fix it...

Trying to debug something this general is tough without some kind of log to work from. The chances of a strictly transient error are slim, so if a log can help us figure out what might trigger the behavior (since we have code to look at as well), that would go a long way to solving the problem.