firefox + java

I tried various things trying to get my firefox 64bit to work with java and flash.
I have now removed firefox 64bit and installed the 32bit version, according to those instructions: Java/How To use Java with Firefox on 64-bit openSuSE 10.3 - openSUSE
but when I start firefox now, the whole computer locks up after a few seconds of running ff.
What should I do now?