WDB FLC CLBS ABOVE ASSIGNED ALT.

Narrative

THE CAPT WAS FLYING. WE WERE CLRED FROM FL200 TO FL230. THE ACFT WAS VERY LIGHT AND THE CLB RATE VERY HIGH; ABOUT 2500-3000 FPM. WITH THE ALT CHANGE CLRNC WE WERE ALSO GIVEN A FREQ CHANGE. THE NEW FREQ WAS VERY BUSY. CTR HAD TO REPEAT INSTRUCTIONS 3 TIMES TO AN ACFT WITH RECEIVER PROBLEMS. THIS DISTRACTED BOTH THE CAPT AND ME. A JUMP SEAT RIDER (OMC) CAUGHT THE ALTDEV AT FL233 AND THE ACFT CLBED TO FL235 BEFORE BEING BROUGHT IMMEDIATELY BACK TO FL230. I CAN SAY WITHOUT DOUBT THAT FATIGUE WAS THE SINGLE LARGEST FACTOR IN THE CAUSE OF THIS INCIDENT. OUR DAY BEGAN WITH AN XA00 EASTERN TIME WAKE-UP. WE ARE A W COAST BASED CREW WHO HAD OPERATED THE PREVIOUS 3 DAYS ON THE W COAST. SO IN EFFECT OUR WAKE UP WAS REALLY XZ00. OUR FIRST LEG WAS EWR-DEN. IN DENVER; DEN-SFO; WE HAD ABOUT A 1 1/2 HR DELAY. 1 HR OF THAT WAS TAKEN IN THE HOLDING AREA; WAITING FOR TKOF. THE EXTREMELY EARLY START; COMBINED WITH A LONG GND DELAY; COMBINED TO MAKE YOU FAR LESS MENTALLY SHARP THAN YOU WOULD NORMALLY BE. THANK GOODNESS FOR THE OMC! THIS IS AN EXAMPLE OF HOW VALUABLE THAT EXTRA PERSON CAN BE. SUPPLEMENTAL INFO FROM ACN 224358: WX WAS SEVERAL LAYERS OF CLOUDS WITH CAP CLOUD OVER MT RANGE. I WAS ATTEMPTING TO NOT FLY THROUGH CAP CLOUD. JUMP SEAT RIDER YELLED; 'LEVEL AT 230' AS I WAS PASSING THROUGH IT.