My client has an Excel workbook that they have used for many years. It has vba macros that use querytables.add to connect to a Sybase database via ODBC and populate cells on a worksheet that they have named "DataSheet". Other worksheets use the data in the DataSheet. This workbook has survived through the various new versions of MS Office through Office 2007. However it does not open properly with Office 2010. The CPU stays stuck at 50% utilization forever and the program is unresponsive to user clicks on tabs, buttons, and menus. It stays frozen. I have stripped out the DataSheet worksheet, and the workbook opens and at least the user can navigate through the tabs, buttons, and menus. I have stripped out all worksheets other than the DataSheet and the problem occurs. 500 points for anyone who provides a solution. TIA.