Which Service Pack are you referring too? There is the Service Pack for Microsoft HPC Pack 2008 and there there is a Service Pack for Windows Server 2008.
I assuming you are referring to the Service Pack 2 for Microsoft HPC Pack 2008. If that is the case, make sure the version of the pack is 2.1.1703 across all the node. You can check the version from Node Management by adding in the column for Version or
using the following PowerShell commandlet: