SHORT SUMMARY: There is a noticable performance degradation between JRE 5.0uX and JRE 6uX when a web-based Java application uses a lot of resource files packed in a single or several big-sized jar files. INDICATORS: The test procedures described by the customer require much more time to finish with JRE 6uX than with JRE 5.0uX. TRIGGERS: The problem happens always with JRE 6uX. KNOWN WORKAROUND: No workarounds for JRE 6uX are known. Both plugin1 and plugin2 demonstrate this issue. PRESENT SINCE: JRE 6 ea b38 HOW TO VERIFY: There is no stand-alone test case for this issue. The support team has reproduced the customer's environment and provided us with access to their testbed. NOTES FOR SE: REGRESSION: yes