MSPEXP430G2 launchpad USB interface

Hello,

I am using mspexp430g2 launchpad with msp430g2553. I am using CCStudio to write and load program in chip. I am able to do so using USB cable. But after programming chip using same program, I try to communicate with PC using hyperterminal or labwindows CVI. The port is open but data is sent and received some time only. Chip fails operation sometimes and suceed sometime in random fashion. Is this problem of UART interface in launchpad? Because from PC side I am successfully writing values to chip but it doesnt send back required values..

Thanks in advance

Shalini