MD80 ON RNAV SID FROM DFW EXPERIENCES LOSS OF TRANSITION WAYPOINT IN FMS ROUTE.

Narrative

DEPARTED FROM DFW ON THE SOLDO 2 DEP FROM RWY 17R. CHKED THE WAYPOINTS ON THE FLT PLAN WITH THE SID AND THE FMS AT THE GATE. GAVE THE RWY AND FIRST TWO WAYPOINTS TO THE QUEUE BEFORE TAKE OFF. ON THE CLB OUT WE EXPERIENCED A PROB WITH THE AUTOTHROTTLES FOLLOWED BY AN AUTOPLT PROB. I WAS HAND FLYING THE AIRPLANE KEEPING THE RANGE OF THE MAP DISPLAY WITHIN 20 MI FOR BETTER ACCURACY WHILE FLYING THE FMS TRACK. THE FIRST THREE WAYPOINTS; TREXX; JOLEN; AND PAXTN PASSED. WE HAD LEVELED OFF AT 10000 FT FOR TFC THEN WERE CLRED TO 17000 FT AND THE 23000 FT ALL WITH FREQUENCY CHANGES. AFTER TROUBLESHOOTING REGARDING THE AUTOTHROTTLE AND AUTOPLT WE SELECTED THE AP 1 AND WERE ABLE TO REGAIN BOTH. WE CONTINUED THE FLT IN AP 1 WITHOUT ANY FURTHER TROUBLE. MEANWHILE CTR ASKED US IF WE SHOWED OURSELVES ON THE ELDORADO TRANSITION. WE WERE ON THE FMS NAV TRACK; BUT AT THAT TIME WE DISCOVERED WE WERE GOING DIRECT TO MEI AND THAT SOLDO AND ELD HAD DROPPED OUT OF THE FLT PLAN. MEI WAS THE TRANSITION TO LGC FOR THE ARRIVAL TO ATLANTA. CTR ADVISED US THAT AN ACR Y FLT HAD EXPERIENCED THE SAME PROB EARLIER IN HIS SHIFT. WE TRIED TO DUPLICATE THE DROPPED WAYPOINT PROB; BUT WERE UNABLE TO REPEAT IT. HOWEVER; ON THE RETURN FROM ATL TO DFW FLYING THE GEETK SID WITH THE VUZ TRANSITION; WE NOTICED JUST PRIOR TO GEETK THAT VUZ HAD DROPPED OUT AND MLU WAS THE NEXT WAYPOINT. WE WERE ABLE TO CORRECT THE FLT PLAN AND FLY THE SID CORRECTLY. UPON RETURN TO DFW THE CAPT WROTE UP THE FMS AS UNRELIABLE.