SoapUI 3.0.1 Pro Slowness / Freezes

SoapUI 3.0.1 Pro I have has following problem which is preventing to perform my work.

1) It takes few minutes to start
2) Once started, it freezes within few minutes, right after I start to use it.

Same problem with SoapUI 3.0.2 Pro version which I downloaded today from nightly build.
(the test case I am trying to run were created in one of the previous version of soapUI, if that is making any difference here ?)

Please note that the free version of 3.0.2 does not have the freeze problem, it works fine. It does take about same time to start up.

What is your system requirement for both pro and free version ?

I have 2G of RAM, is that too less ?

here are the defult settings from .vmoptions file

-Xms128m
-Xmx1000m

Please help me fix this issue.

thank you

Jignesh