>Well, on my keyboard shift and ctrl are just as close together as 4 and 5.

OK, how often do _you_ press Ctrl when you meant to press Shift? :)

>Seems like something that could happen pretty easily. So you're saying that when you did data entry you didn't have to hit the back-space many times per day?

Define "many." :) In my case, certainly less than 100. A good data entry operator does one thing well: translates (usually) printed data into keystrokes. At a certain level of competence, this is completely automatic. I could spend hours without consciously even thinking about what I was doing.

>Ctrl-Z removes the NULL, but doesn't restore the data.

Well, that sucks! :)