Performance Impact of Application Packaging in WebLogic 8.1 SP6-EAR vs. WAR

We are faced with a strange situation.

We recently moved all EAR components to WAR - without changing the base Weblogic version (8.1 SP6). Right after the repackaging, we saw stronger> efficient CPU utilization on the servers. We ran several tests, and based on the results, our current theory is that the reason for this is the differences in library inclusion (APP-INF / lib in EAR and WEB-INF / lib in WAR).

Does anyone else have any experience / war stories / thoughts on problems with this?

Thank!