a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS038 [Section] 5.1.1 [Statement text] 
If the Producer returns an InvalidSession fault message after returning a sessionID, the Consumer MUST NOT resupply that sessionID on a subsequent invocation and SHOULD reinvoke the operation that caused the fault message without any sessionID and supply any data that may have been stored in the session.
WSRP v2.0 Specification
Statement text