I noticed that when I closed by Excel application an instant still remained in memory (Excel.32* process in Task Manager)

I spend ages googling for an answer and applied all the given ideas, that is set all objects to nothing, removed all unused references etc. But still no joy. I then thought it might have been the customized ribbon I had created so I removed that. Still no luck. I then systematically removed forms one at a time and then all sheets except a blank default sheet 1. Still no luck so I started removing all module (most code had pretty much been commented out by now anyway). I was now left with just a bare workbook with one worksheet with no code, no forms, and no modules. And it worked. The excel process was removed from Task Manager. By now I had no idea what to do so I thought I would just enter some test code into a module. I added a module and then some code. After closing down there was no erroneous entry in Task Manager. It was then that I realized that the what I was doing differently. In this case I had saved the workbook before closing. In the other tests I had been opening the Workbook and them immediately closing.

So to make a long story short - If I saved the Workbook before closing then all Excel processes finished. If I didn't then one process remained in memory. I tested this out again by creating a completely new Workbook and adding a module to it (no code in the module). If I closed without saving then the problem occurred. If I save then no problem

So - can anybody enlighten me on how to get around this issue?

P.S - I'm using Office 2013 on a Windows 7 64bit platform

Thanks
Rick