I am using Office 2010 with Windows 7. A strange quirk has developed in the recent files list of Excel...the recent files on the Excel app line of the the start menu now only shows workbooks with the Excel 2007 file extension of .xls. Files with Excel 2010 extension of .xlsx no longer show up in Excel's recent files on the start menu (they do show up on the Windows/Start Menu recent files list, however). This seems to be happening only with Excel; the other Office apps have no probelm displaying the Office 2010 file forlmats.

Any ideas on what's going on here and how to correct it? Thanks in advance.

Paul