get the latest Java runtime from Sun (http://java.com/en/download/
The latest Java Runtime is available from Sun´s main site. The Runtime available from Java.com is several updates older, strange enough.
On my Dell 500m laptop with running Win XP Pro SP2, I had already Java Runtime 1.5.0_07 when TR wouldn´t start properly (at all, in fact).
It was installed over a month ago and, yet, it was newer than the version offered att Java.com. At the same time Sun.com had an even newer than I had onboard.
Was installed on laptop:J ava Runtime 1.5.0_07
Offered at Java.com: jre-1_5_0_06-windows-i586.xpi
Offeret at Sun.com: jdk-1_5_0_09-windows-i586-p.exe