I'm checking out Excel workbooks with VBA and sometimes I just want to
discard the check out and close the workbook. I've just started to get an
error on this line

myWB.CheckIn ( False)

Run-time error '-2147467261 (80004003)':

The check out cannot be undone ...

If I press F8 to continue, it moves right along..

FWIW, this update was recently installed (but I don't see how it might
affect what I'm doing)

http://support.microsoft.com/?kbid=969898

Thanks,
Barb Reinhardt