ctrlc()/tstc() never responds

Hello,
On my system the ctrlc()/tstc() never responds. I could not press Ctl+c to abort an operation like mtest,tftp etc or any other operation that calls ctrlc() to abort operation. What I see is that tstc() never returns for key presses in ctrlc(). But in uboot prompt, Ctl+c is caught and I get <INTERRUPT> printed out. Has anyone experienced such problem before.I am using top-of-git uboot tree.

Thanks,
Shiju