I created an Excel spreadsheet that auto-generates 10,000 product SKU's from a list of words. I kept getting "#VALUE!" errors using the LOOKUP function in Excel.
The answer was to press CTRL-SHIFT-ENTER when entering the formula! Weird...
http://en.allexperts.com/q/Excel-1059/2008/1/match-index-formula-giving.htm
By using an "Array Formula" the errors went away! Very pesky bug to chase down, figured I'd post it here.
The weirdest thing, I only got the error after 1,000 rows... And such.