VFP has a nice feature that it self register the OCX. If it is not already registered, VFP first looks for ActiveX control in the current working directory then in the path.
In your application before going to ActiveX control issue this command,

! /n regsrvr32 /s /u MSCAL.OCX or any other OCX file that might be conflicting with other version.

Above command will unregister the MSCAL.OCX and VFP will register
it again with correct parameters.

Try to keep all OCX in current working directory instead of Windows\system directory. Upgrading an OCX in windows system might create problem for other
programs.

Regards,