Toplink & undeploy file locking
This is most likely related to the on and off discussions going on here concerning JARs that are unable to be deleted during an undeploy or redeploy. At least in my particular case, on Windows using v2b16, it seems isolated to Toplink. The only JAR that GF is unable to undeploy or generally delete (until the server instance is shut down) is my persistent entity JAR.
Just an FYI, comments from others, etc.