Software Deployment

Hi all,
I am beginning to deploy windows 7 in our environment and have run into a snag. We use group policies to deploy our printers, and when a printer is installed, the PendingFileRenameOperations value in hklm\system\currentcontrolset\control\session manager\ . After a printer is deployed, many of our .msi's won't deploy stating that a reboot is pending. However, some msi's don't care and will deploy no matter if this reg value is populated or not. I'm wondering if anyone knows why some msi's work when this value exists and why others won't. I'd like to modify all our msi's to ignore this registry key if possible so that we don't image a machine and wait for multiple reboots before the machine gets all of its software deployed. Thanks