No ActiveX controls when reading 2007 file formats into Excel 2003
 

When I open workbooks in .xlsm format in Excel 2003, I get the warning
"Uninitialized ActiveX controls will not be opened in this version of
Excel.." The file is then opened as Read Only. These are not exotic
controls. Just combo boxes and command buttons. Am I missing some update in
addition to the Compatibility Pack that will allow ActiveX controls and
macros saved in 2007 .xlsm to function when converting to Excel 2003?