Thanks for the response Maciej. It did work with jBPM 4.3 as well, but the response in quite sporadic. At times, it runs perfectly, and at other times it throws the above mentioned errors. It goes into an inactive-scope for state and does nothing beyond that.
Anyway, I tried it with jBPM 4.4, and it seems to work now. But our project technology landscape includes jBPM 4.3 as of now, so was looking for a solution in the same version.
Thanks anyway.
Rgds,
Prachi