An MD80 Captain believes his latest encounter with maintenance malfeasance--an undiagnosed pressurization problem--is symptomatic of a purposeful attempt to operate aircraft despite limited or failed maintenance diagnosis of repeated write ups.

Narrative

At the gate I reviewed the logbook and found 2 repeat write ups; both identical. During climb pressurization flow light on. Cabin climbing outflow valve closed. During climb we experienced the same thing; the condition lasted about 30 seconds while the cabin climbed and then the light went out and the cabin went into a descent. When the cabin got back on schedule it climbed properly. We continued flight while discussing whether to continue or head back to our departure station. I called Maintenance Control and the gentleman I spoke with thought it would be OK to continue. We decided not to fly for 3 hours at altitude with a questionable pressurization system. The maintenance response for the 2 prior write ups was '...could not duplicate; OK for service'. Our airline is continuously placing aircraft in service without the proper troubleshooting for [proper] diagnosis. Our Maintenance Controllers have been trying to diagnose over the phone like a computer technician does. Two other instances prior to this example; were barely addressed.