OpenJDK: Rubymine Editor Much Slower using openjdk than sun jdk

FULL PRODUCT VERSION :
saturn:~ $ java -version
java version "1.6.0_18"
OpenJDK Runtime Environment (IcedTea6 1.8) (6b18-1.8-0ubuntu1)
OpenJDK 64-Bit Server VM (build 14.0-b16, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Ubuntu 10.04 64 bit

EXTRA RELEVANT SYSTEM CONFIGURATION :
Dell M4400 laptop.
VGA compatible controller: nVidia Corporation G96M [Quadro FX 770M] (rev a1)
4 cores
4 GB RAM

A DESCRIPTION OF THE PROBLEM :
When using the Rubymine IDE, I experience major performance degregation when compared with running it on Sun Java 6.

I previously filed a bug report to Jetbrains at:
http://youtrack.jetbrains.net/issue/RUBY-5954?projectKey=RUBY
They may be able to help here.

Basically using the UI in Rubymine is much slower with openjdk. Specifically, opening and closing the project panes causes cpu spikes.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Install Rubymine.
Open a sizable project. e.g. http://github.com/btakita/rr
Open and close the project pane

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I expect it to not be slow and not be cpu intensive.
ACTUAL -
It is slow and cpu intensive.

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Use sun java 6.