I think when you changed to 2007 you probably lost your copy of mscal.ocx
this can be downloaded from a number of sights just by doing a quick search,
you must register mscal.ocx after you have downloaded it.

"Canon" wrote:

Excel 2007
When I installed Office 2007 on my new computer, a file with a Date Picker
will not work properly. I can install a new date picker and it will work
until I shut down the file and re-open it, then it stops working, (just get
the red x).
Also when opening this type of file, it takes a least a minute to open.