I wouldnt say she has a QF curse at all the slams but I would for sure say she has one at Roland Garros. It all goes back to that 2003 French Open SF Henin def S. Williams 6-2 4-6 7-5.
The tough part for Serena had to be that she was leading this match in the 3rd set. I don't feel this completely changed Serena's career because she obvisouly went on to win Wimbldeon right after this loss, however she was defending champion at the FO she had proven she can win here and in the midst of the "hand" incident the crowd totally went against her. Serena lost her focus and Justine took advantage and the match. Following this loss she has NEVER gotten past the QF in Paris.
I hate when people say her 02 run was a fluke or anything close to it when she beat the defending champion in route to slam #2 in Paris but I think this loss to Justine in 03 just tarnished Serena's record at the FO. Had she not won so emphatically against Capriati in 02 she wouldn't have the career slam and the 02 FO started her Serena Slam.
04- L to Capriati in QF 6-3 2-6 6-3
05-06- DNP Serena (has missed the FO 4 times in her career more than she has missed any other slam)
07- L to Henin in QF 6-4 6-3
08- L to Srebotnik in 3R 6-4 6-4
09- L to Kuznetsova in QF 7-6(3) 5-7 7-5
10- L to Stosur in QF 6-2 6-7(2) 8-6
12- L to Razzano 1R 4-6 7-6 (5) 6-3. (There is no coincidence Paris has had some of the worst moments in Serena's historic career)
All of these losses it just seems in close situations the FO (especially the QF) has been the ONLY exception to Serena's great play at slams. She is usually always been capable of saving MPs and coming back to win a tight match in a GS situation but in Paris it has not been the case. She has lead in many of these losses and besides 07&08 she took a set.
IMHO Serena has a mental block in her matches and she is never able to get herself over the "hump" in the QF or in Paris in general.
I hope this is the year she can break the "curse."