I have had a copy of Quicken Premier 2010 , a personal finance program, for several months now. I can't be too negative as I have been using it and it has saved me some money but it certainly has annoying aspects.
One of which is the data entry is quite buggy in a strange way. Sometimes when you correct a mistaken entry the change is not correctly propagated throughout the program. Traces of the mistaken entry remain fouling things up. I generally have been able to find work arounds (although one case still has me baffled) to force the program to accept the correct data but it is really annoying. In my opinion it also reflects badly on the program design. It seems like the program has a lot of hidden state, previously calculated intermediate values and the like, which can cause problems which are hard to diagnose as the hidden state is invisible to the user. It seems questionable that any gains in computation time are worth the added complexity and error potential. At a minimum it seems like there should be some way to force everything to be recalculated from scratch when the program gets confused.