Excel will not Auto Refresh external data when opening file

[AFSkier]

How come Excel will not Auto-Refresh external data when opening file on all PCs? Only 2 of 5 PCs in our office will Auto-Refresh the data when the Excel file is opened. It is that way with all Excel file with external data connections. All of the PCs can manually refresh the data. All are nearly identical, running Windows XP & Excel 2007.

The Connection Properties for the file is set to "Refresh data when opening the file". Yet only 2 of 5 PCs will Auto-Refresh on open.

I've checked all PCs to make sure the Macro Settings are set as follows:
*Macro Settings: Enable all macros
*External Content: Enable all Data Connections
*External Content: Enable automatic update for all Workbook Links

[Don]

Do you have any anti-virus programs that may be affecting it? For instance, I run pretty strict access controls through my anti-virus program and this prevents some functionality in MS Office from working until I tweak a setting or two in the anti-virus program.