[AccessD] Function User Log error

I guess it would help if I used a subject line, wouldn't it:>
I use the function below to log users into and out of a database.  The 
database is split with the BE on a server and using AutoFEUpdater to place 
and update the Front end on the users C:\Drive.
However, when I deployed this database yesterday, something strange happened, 
some users get an error message saying an updateable query must be used, and 
others do not.  For those with the error message, the main menu form does not 
open or is hidden, but they can open it from a toolbar I set up, then go on 
about their business.
I have narrowed the problem area to the function below.

All the machines have the same configurations, and references(?), only 
difference is that there are 2 sides to the LAN, an FAA side and a NG side. 
But we can all get to and have permissions to the proper folders (obvious 
since everyone can actually open the database and work)


Any ideas welcome,
TIA
Nancy Lytle

CODE:
Option Compare Database
Option Explicit
Public bolUSERLOG  As Boolean 'enter exit flag

Public Function fcnLogUser()
Call fcnOSUserName
Call fcnUserGroup
Dim strSQLInsert As String
MsgBox "User entering/exiting"
'DoCmd.SetWarnings False
If bolUSERLOG = False Then
strSQLInsert = "insert into tblUserLog(UserName, UserGroup, UserEnter) values 
('"
strSQLInsert = strSQLInsert & fcnOSUserName & "', '" & fcnUserGroup & "', #" 
& Now() & "#)"
MsgBox strSQLInsert
Else
strSQLInsert = "insert into tblUserLog(UserName, UserGroup, UserExit) values 
('"
strSQLInsert = strSQLInsert & fcnOSUserName & "', '" & fcnUserGroup & "', #" 
& Now() & "#)"
MsgBox strSQLInsert
End If
DoCmd.RunSQL strSQLInsert
'DoCmd.SetWarnings True
End Function

-- 
Nancy Lytle
EIS
nancy.lytle at auatac.com