Same model but Convergence Problem

Hi

I have a model (using solid mechanics and heat) which is setup in 4.2a and I get excellent convergence. I have alos setup the exact model in 4.3a no changes been made in any boundary conditons or anything else. Why my solution is not converging in 4.3a? I have to manually cancel the calculation everytime because it doesn't converges to my prescribed relative tolerance. In both models I have used automatic scaling.

Can some one please explain what could be the reason.