SaveCopyAs. Code Failing To Fire.

I have an Excel 2007 workbook with over a dozen user forms and plenty of code that I have mainly obtained from the web and tweaked to suit my needs. I am a novice with VBA, so not really up to writing anything but quite simple code.

My issue is I have some code set to fire on Workbook_Open that will save a versioned copy of the workbook, to the same network folder that the original resides in, with an incrementally increasing file name. the file is stored on a network, but access should not be an issue as I have full access and have no problem saving to this folder, also the event works fine up until I shut down Excel. I have also tried saving to My Documents to avoid the network issue, same result, worked fine as long as Excel is not closed, fails if I do.

It all works fine until I close down excel completely and re-open, where it then fails to work. There are other events happening in the same Workbook_Open sub that still work fine each time, so the sub is firing on open, but this one event fails. I get no error message at all, just no new file copy created.

The workbook is essentially doing the job of an Access database (I know even less about Access), I have a user form as a main menu and various other forms for various data entry and reporting tasks. I am exiting the w/book via a cmd button on the main menu (I've deliberately restricted users control, as many are not very pc literate). I have conducted numerous trials consisting of running the code from the VBA window, closing w/book via cmd button WITHOUT accepting the std save option and re-opening from Explorer window, closing w/book via cmd button WITH accepting the std save option and re-opening via Explorer and all worked perfectly over many sample runs. But when I closed Excel totally (Not just the w/book), created a desktop shortcut and opened from there, that line of code just doesn't seem to do anything, no error or hang or anything. The only way I can get it to function again, is to re-save the w/book (As either a new file with code edited to suit, or overwrite the original), and keep Excel open whilst only closing this w/book. It then functions perfectly again on opening.

I have enclosed below the Workbook_Open sub and some other subs that append to a user log on opening, these work fine all the time. I enclose the others in case they may have some bearing, as they are also fired from the Workbook_Open sub and show no issues at all.

Any suggestions gratefully accepted as I am struggling. As mentioned above, the ONLY part of the Workbook_Open sub that fails is the line "ThisWorkbook.SaveCopyAs newFileName". I have even added "MsgBox "The new FileName is: " & newFileName" immediately after it, and that displays new filename correctly. It seems to me to be hingeing around the SaveCopyAs event, but I don't want to assume that, being the novice I am.