Not sure this is the issue but can you add zero-arg construtor to this class and try...
[warning 2013/06/15 08:44:01.878 PDT vDevUsvr51 <Function Execution Processor1> tid=0xbc] Class com.coupons.gemfire.domain.GwTransactionMaster matched with 'com.coupons.gemfire.domain.*' cannot be auto-serialized due to missing public no-arg constructor. Will attempt using Java serialization.