“If you have a spreadsheet that uses the RAND() function, and you’re using Excel 2003, you may be getting bad results – and you probably don’t even know it. Excel 2003’s RAND() has a big, big bug in it. In short, RAND() should produce a pseudo-random number between 0 and 1. Microsoft reworked the function for Excel 2003 so that it would produce a better quality of randomness, especially when you ask for a large number of random numbers. Guess what? If you do try to get a lot of random number, the function gets buggy, instead of numbers from 0 to 1 you start getting negative numbers. If that weren’t enough, the negative numbers aren’t sufficiently distributed to be considered ‘random’. And to top it all off, Microsoft has been told about the problem and has done nothing. Like serious Excel problems in the past this new bug has been ignored.”

Update on this story:

“Lot’s [sic] of talk about the RAND() bug in Excel 2003 - but a stony silence from the one place you’d want to hear from - Microsoft.”