Yes, sometimes bugs crop up-- theres so much going on every time you hit the interval button, and it doesn't tolerate wonkeyness extraordinarily well.
I have problems with Cycleorders frequently; sometimes the orderlist gets duplicated a billion times.
Next time one pops up, search for the error number in the top right of the forum to see if you can get any details, or scroll through the forum thread in the Aurora Bugs section for your version number.
Good luck and enjoy!