The 3356 error is telling you that you dont' have exclusive access to the database. If you want to supply a passoword, that's fine, but at some point, you're going to have to address the 3356 error.
There's code in the ng_Step2 routine that looks like this:
If strFileName = "C:\MyFolder\MyFileName.mdb" Then
DBEngine.CompactDatabase strFileName, strFolderPart & strTempFileName, , ";pwd=MyPassword"
Else
DBEngine.CompactDatabase strFileName, strFolderPart & strTempFileName
End If
You can modify this code to supply a password for a specific database.
hope this helps,