Losing VBA code under 'ThisWorkbook' (Private Sub WorkBook_Open() )

First three elements of the background:

I have created a Excel Template which is used, in turn, to create a 'personalised template' where user name, user comment, and save data pathnames are embedded in the personalised template.
The personalised template is used to produce monthly workbooks (actually, time sheets)
The template has been created in Office/Excel 2007 running under Vista but the (current) target environment is a corporate network running Office/Excel 2003 under XP Professional. Both templates are therefore created as Excel 2003 templates (which in the development environment run in compatibility mode)

So far, so good - the templates work well in the development environment - the 'personalisation' code is in a WorkBook_Open() routine under 'ThisWorkbook' - it runs, DELETES ITSELF, and saves as the personalised template. Both templates have the 'process macros' in the Sheet1 code (the principle here is that the initial template has macros in 'ThisWorkbook' and 'Sheet1'; the personalised template has macros only in 'Sheet1' and the workbooks created from the personalised template have NO MACROS AT ALL.

In 'beta testing' I had problems with Excel2000 under XP (fileformats) and on a target machine my WorkBook_Open routine was deleted in the main template (instead of in the personalised template) - even though everything worked OK on Excel2007/Vista.

I felt at the time that the invalid deleting of Workbook_Open was probably a coding error -but whilst researching the issues I found a number of references to 'Macafee deleting VBA modules'. I did not look into these - but was conscious that the target machine (and environment) run Macafee whilst all my computers run Norton.

Having recoded, I successfully retested in the following:

a) Excel 2007/Vista/Norton
b) Excel 2007/XP Professional/Norton
c) Excel 2000/XP Home/Norton

so felt comfortable to re-test in Excel 2003/XP Professional/Macafee

This time I was watching for it - so, once again, saw the WorkBook_Open routine incorrectly deleted from the main template - unfortunately this was only moments before the USB Memory Key (where the template was running from) was completely destroyed.

So to the question(s) - before I go through the whole process again:

Is there any objective evidence of Macafee removing 'auto-run' VBA modules?
If yes, is there any work-around (this template will be use by three people in a enterprise of ten thousand - so there is no way I will be able to influence/modify the security policies!!! :( ) - if there is a problem with Macafee then I will have to re-think the whole thing!

Solution

I have managed to get to the client machine again - and added a new simple template to prove or otherwise my issue. The new WorkBook_Open routine is...

Private Sub WorkBook_Open()
    MsgBox "Hello World"
    With ThisWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule
        .DeleteLines 1, _
        .CountOfLines
    End With
    MsgBox "Goodbye to all that!"
End Sub

...and this works exactly as required i.e. the routine executes then deletes itself (the second msgbox displays even though the code has been deleted!

So, this test invalidates my question - McAfee is NOT deleting the routine as part of AV protection - so I am no longer looking for a workaround!

Now all I need to do is to figure out what my problem really is!

Thanks for the comments