Hmm, their is an easy fix to this first go to your "Local disk C:" then click "Program files" and find and click "Java" now if you have Jdk it will show up and say jdk_1_0_4 or something like the one with the highest number after jdk you click on the file copy the location of that file. Now you go to run on the Uberocity client right click and cick edit, now you will see this
@echo off
cd ./bin/
@title Uberocity
"C:\Program Files\Java\jdk1.7.0_04\bin\java.exe" -Xmx1024m client 0 highmem
pause
Now you want to highlight from the (C) to the 04 then right click and paste. This should work, if you do not see jdk in your Program files download it right here
http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1637583.html, click "agree" then select one, which ever system your running if your running a 32 bit pick the x86 version the rest is the same.
This video explains how to do it too, instead of doing it to the compiler do it to the run.
-Zer0