waterinjection.info - failsafe CEL question

My HFS-6 is performing well from what I can tell. However, I have now had on three separate occasions a CEL tripped on startup. What normally happens is after I have been driving for a while, park and then restart the car the failsafe triggers the code that must then be reset. Each time this has happened the amb. temp has been >95 degrees, No problems on initial startup at all, I'll run to the store, or drive my commute home, head out a second time and on the restart the code (wastegate sol A) is setoff. The performance of the spray seems fine, etc. Any suggestions will help. Its not real problem, more of a irritant. The ecu takes a day or two to relearn parameters, timing adv, etc. after a reset.