Oh that is a shame if it is toe tapping.

I still cannot find any info on ringies getting it though.
You could try adding a calcium suppliment to the water and provide cuttle bone as well.
Does your ringie spend any time in natural sunlight?
Sunlight helps in the absorbtion of calcium also there has been some success of toe tapping in eckies when sunlight is provided.
Another thing that could be triggering toetapping is zinc or other poisioning, neuropathy, or excessive vitamin supplements.
Is there a avian vet near by where you could have a more expert opinion?
Here are a few links to toe tapping in eclectus parrots. May be of some help.
http://www.avesint.com/toetap.html
http://www.eclectusbreeder.com/toetapping.htm
http://www.eclectusparrots.net/toetapping.html
Hope you can find the sorce of the problem and all goes well.
Fingers crossed for you.