when you create the package make sure you are selecting the MR5 package on the right hand side.
select the MU5 on the right hand side , export it .
run it on the clients, check if its rolling back or something.
To create the new custom install package
In the Symantec Endpoint Protection Manager Console, on the Admin tab, under Tasks, click Install Packages.
The current default client installation packages appear on the right.
Under View Install Packages, click Client Install Packages.
Under Tasks, click Export client install package.
Browse to or create a preferred export folder, and select it.
Select whether or not you want to create a single ".exe" file.
Select Installation Settings and Features.
Select Custom Install Settings from the settings drop down.
Select Custom feature set from the features drop down.
Select the group to which the client will be installed. If no group has been created, select the Default group.(Or you can make the client as unmanaged)
Select the Preferred Mode. The default is Computer mode.
Click OK.
The new install package is created in the location that you specified