Apparently Microsoft decided to disable a feature my company has been using quite a bit. We have a bunch of formulas residing in both XLA's and XLL's that return arrays. Some of the workbooks we use these formulas in are shared. Apparently, you are no longer able to share such spreadsheets. They will keep sharing on if it was created in a different version, but if you have to remove sharing to modify an array you won't be able to share that workbook again. We talked to Microsoft and they suggested that we use Excel 2000 to modify those sheets, share them and then open them again in XP. Not a very convenient way. I'm wondering if anyone has encountered this problem and has a more elegant solution.