Closing open xlsm workbooks individually

[Scuff]

OK, so I've got a few Excel 2007 workbooks containing macros. It seems that sometimes when I want to close one of them I must go through and save and close all open excel documents first. Until I do the close button does nothing, neither does right clicking on the task bar and hitting close or File and close or Alt+F4, etc etc. Only after closing every other open excel document first can I then go back the one I want to close and close that too.

They're opened in individual windows (it's not the old click the little X and not the big one problem), and there are no macros or processes that should be running at the time of trying to close. It doesn't happen all the time, I've just opened 2 workbooks I use frequently and closed them individually without a problem. I haven't yet found a trend as to when it occurs, although I'm sure there must be one.

It something I can cope with, an annoyance but in a way a good way of forcing me to make regular saves I guess. But I write these for other people at work to use and frequently get asked "Why does it do that?". I hate having to admit that I have no explanation!

Any one come across this? My Google-Fu has failed me thus far...

 

[Scuff]

Bam! Found the cause!

The workbook is protected, and I was wrong, I was opening it in the same instance of excel as some other excel docs.

Solutions:
1. Don't protect the workbook (needless to say it's protected for a reason so I won't be doing that)
2. Deliberately open a new instance of Excel and run the workbook in that to segregate it from my other open workbooks (hassle, and not suitable for my users)
3. Probably the most likely solution - Write a close macro to save the workbook, unprotect it and close it, and add this to a nice chunky button on the front page.