Excel 2010 Shell does not close completely

[msgBldr]

This has started in the past month or two:

• I have a workbook open, only one.
• I close Excel using the X in the upper right hand corner in the outer frame.
• The open workbook closes but leaves the shell open with no workbook.

Some notes:

• This used to close the shell as well as the workbook.
• It only happens on my win7 machine, not on win10.
• I'm opening files in both machines with the /x switch.
• This is Excel 2010

It's making me crazy, any ideas?

Thanks in advance... Bob