Raj,

Ferrite beads or surface mount ferrite devices can be put on the board on every line that goes to the outside world. Also RC filtering on each line that goes to the outside world. This will limit the EMI/ESD that is at present locking up your uProcessor.

I have had similar problems in the past and now incorporate this circuitry into all of my designs.

When you redesign the PCB, you will want to make sure that the ground plane is sufficient, if it must stay a two sided board, then increase the size of the ground traces.

Regards,

Jacob