MLG CREW IGNORED TCASII RA COMMAND AND ALMOST CAUSED A DISASTER.

Narrative

CLBING THROUGH 5000 FT; FO FLYING THE ACFT; WAS TOLD BY DEP CTL TO TURN R TO 360 DEGS. WE CONTINUED TO CLB TO 10000 FT. AT 8500 FT THE ACFT'S SPD WAS 240 KIAS. 'OVERRIDE 320 KIAS' WAS REQUESTED AND SELECTED ON THE FLT GUIDANCE PANEL. AS THE NOSE WAS BEING LOWERED PASSING THROUGH 9300 FT; WE OBSERVED AND HEARD A 'TFC' TCASII ADVISORY; FOLLOWED IMMEDIATELY BY A 'MONITOR VERT SPD' WHICH COMMANDED A MINIMUM RATE OF CLB OF 3000 FPM. THIS COMMAND WAS FOLLOWED MOMENTS LATER BY A 'CLB; CLB' AUDIO COMMAND. A VISUAL SCAN REVEALED ONLY ONE ACFT AT OUR 1 O'CLOCK POS INBOUND ON THE ROME STAR. I INFORMED ATLANTA DEP CTL WE WERE UNDER AN RA CONDITION. DEP CTL INFORMED US THE TARGET HAD BEEN CLRED TO 11000 FT BUT HE WAS 100 FT BELOW THAT ALT. IT WAS MY JUDGEMENT NOT TO FOLLOW THE TCASII GUIDANCE. I TOLD MY FO TO LEVEL OFF. THE INBOUND ACFT PASSED 500 FT ABOVE US. I THINK THAT IN ACFT PROBS WITH TCASII WE NOW HAVE; ALT SEPARATION BTWN INBOUND AND OUTBOUND ACFT BE 2000 FT TO PREVENT THESE 'POP-UP' TCASII RA'S.