I recently discovered that Excel 2003 seems to invoke Functions when rows are hidden and unhidden. I have a rather large spreadsheet that I've used for years, and it has several custom functions and macros. The macros basically hide and unhide rows based on selections a user makes, and the functions are just basic stuff. I have proven that in Excel 2002, the functions are NOT called when rows are hidden or unhidden, but the same spreadhsheet opened in 2003 DOES call the functions when rows are hidden/unhidden. The result of this is it is VERY slow...Keep in mind, it is NOT the macro because even if you just highlight a bunch of rows, it is slow, BECAUSE it is calling the function. Does anyone know WHY it thinks the function needs to be called?

Thanks,
Steve