Hi Koen,
Thanks for your quick response,
my jvm is:
java version "1.6.0_27"
Java(TM) SE Runtime Environment (build 1.6.0_27-b07)
Java HotSpot(TM) Client VM (build 20.2-b06, mixed mode, sharing)
and the forge tools version is:
1.0.0.v20110915-1403-H14-M3
I will give the nightly build a try ...