Hmm, I use families all the time without problems... The only bug I'm aware of is if you give a family behavior specific instructions, but not all members of the family have that behavior. Then again it shouldn't let you give those actions, but I recall the bug being somewhere along those lines, either with shaders or behaviors. Well, if it's getting too annoying, feel free to pm me the cap and i'll have a look. If you want to keep your game secret, then that's fine with me too.
Also, make sure you pick a family member before giving actions to it. That's what I usually do and it works without problems.