Map and collection classes 10 - 30 X slower than kestrel and ladybird release on linux RH6.1 when -server flag enabled. This may be tied to io since io performance seems similarly affected.
To recreate the bug:

java -server -version
java version "1.4.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta-b46)
Java HotSpot(TM) Server VM (build 1.4beta-B45, mixed mode)

java -server -cp /net/perf-lnx/export/performance perfteam.jetstream.JetStream -r 5