I am trying to be a good open-source software proponent, thus I’ve been using OOo Calc for my spreadsheeting needs instead of Excel. Sadly, I’m giving up on it. The problem is not a lack of features, rather, without explanation, OOo Calc will suddenly use 100% CPU for intervals measuring in the tens of seconds, at which time it is totally unresponsive. To my amazement, this has not resulted in any crashes. Still, it is unacceptable. I hope this is a known issue and will be resolved soon.