Hmmm. My game was just recently re-installed when I bought the Pets expansion a few weeks ago. The few times that I paid attention to what the sims were actually doing, it was something like the father emptying the potty contents into the commode or the mother standing at the dishwasher while thinking about picking up a toddler. I have been able to "X" out their existing queue and tell them to "go here" and all is well until the next episode occurs.
The only sims I have played otherwise are the Curious brothers and I have received no errors there, so you may well be onto something with the CAS thing. Darn, and these were people I had planned to spend sim generations playing.
Thank you, Two Jeffs.