it dropped by 30k in one day

Ok, the problem with the RAC is fixing itself now. For some reason 12 hours ago was correct, but this mornings RAC dump was wrong, so the network is re-downloading the rac now, and within the next 100 blocks or so the sancs should see the correct rac.
If you reboot your client you should see the correct rac right now, but sancs will take a little while to update (I believe its every 50 blocks or so).
I don't believe this will be a reocurring issue knock on wood, as we didnt run into this in testnet.