jbuilder4 won't run with merlin-beta, build 75

The jbuilder startup script runs java. java runs for a few seconds and
then exits with no errors.

This also fails on win32. It works ok with build 74 on both platforms.

To reproduce, you can probably run my jbuilder:
cd /net/mmm.eng/export/mmm/jbuilder4/bin
./jj.sh

This will run build 75. To see it work correctly with build 74, do

./jj.sh -jdk \
            /net/jdk.eng/export/disk6/promoted/jdk/1.4/beta_refresh/b74/binaries