I have the same problem. No idea how to proceed.
Fresh loadui installation (installed as root user into /opt directory).
Notice: I first had to remove the packaged jre directory and change the startup script to use the jre of my machine (also Java 1.6 though) to get this far.
Otherwise I would just see a Java webstart banner for a while, but nothing would happen. (Error encountered while invoking Java Web Start(execv): No such file or directory)
I got it running on a CentOS VM now, but so far, trying to use LoadUI has been pretty frustrating for me...
