One of Excel's many wonderful quirks, like the fact that it can't open more than 1 file with the same name, or that (in some versions at least) you can't open a file from File->Open if the path to that file has certain 'special' characters in like [ ] & even though they are perfectly validly characters for a path in Windows Explorer and the file will open in Excel if you double click it in Explorer.
Biting the hand that feeds IT
