Customer is running 3 applications inside a JVM. They have been running on 1.4.2_05, using CMS. They recently evaluated 1.4.2_08 and 1.4.2_09 and found that with 1.4.2_09 they were seeing OOM errors  whereas things ran stably (at least without OOM) with 1.4.2_08 and earlier.

They experimented with swapping JDK and JVM vintages and found that the problem was in the 1.4.2_09 JVM.  They found that the problem persisted with latest 1.4.2_11 release as well.