Frequent parse error for sql running in parallel mode

Hello experts,

                       I have been observing frequent parse error for a specific SQL which is executed from an application job.This parse error is flooded in database alert log and I can see the same in diag trace files of huge size.When I start looking into trace file I see most of the time it is waiting for 'Cursor pin S wait on x ' event and one parallel slave is blocking other parallel slave.For example below is a snap from diag trace file.

Oracle session identified by:

{

instance: 1 (mdmp2.mdmp2)

os id: 34783

process id: 1344, oracle@mdmprod2 (P032)