Sinking Feeling

Can anybody help, I have a disk on which I stand and move as a physics object. Before the current Server release it flowed along quite well. Now it slowly sinks in the floor only a certain distance, not down to natural ground level I wondered if my avie was stopping it going any further.
By setting hover to 2 metres above the floor level I can move just above the floor, but when I stop to perform an animation I sink into the floor again.
This is definitely a Havok physics problem.
I just wondered if anybody had a work around?

Since the whole physics system (Havok 1) has been replaced by a new one (Havok 4) this may require a rescripting or adaption of the code to the new, far more detailed physics you are now able to enjoy.