>Seems to me like trapping it is a good idea.

Like I said, I don't think there's anything wrong with trapping it. It certainly does no harm. I was just wondering about the accuracy of those particular users if this was a significant enough problem to bother with. After all, data isn't lost--it can be rekeyed. Whether this is especially onerous depends on how often they hit Ctrl+0.

>Every data entry person in the world probably makes a hundred typing errors a day.

I don't believe this is the case, though. I used to do data entry eight (or more) hours a day. When you're doing data entry full-time, you simply need a higher level of accuracy than that. Mixing up the Ctrl and Shift keys isn't exactly like typing a 4 instead of a 5.

I wonder if pressing Ctrl+Z would bring the data back?