Mean Streak

[Brian_Z]

My current household has 2 children.  They keep getting the Mean Streak phase, over and over!  It's infuriating!  Especially now that we have Sentiments, so now a kid decides to be a little snot for a couple of days and the whole family ends up hating his guts.  Cheating the phase off doesn't seem to actually work, you can remove the temporary trait but they continue acting like that anyway.
Is there any cheat or mod that will block Mean Streak entirely?  The only other solution seems to be to lock the kid in his room until the phase ends!