I had this problem too, got two achievements then they stop to pop, I was at league 4 with only those two achievements.
Coincidence or not I had a problem with my pc and need to format and reinstall the OS (W7). After that I reinstalled the game and update the GFWL client ingame (the default was that old grey one) and when I back to the game, I did the 2~3 goals remaining in the league 4 and, for my surprise, achievement unlock, did some more races and "Tuned" and "Feelin' lucky" popped too.
Then I started a new career to try the Leagues 7, 6, 5 (I've tried to redo some goals at those leagues in my actual career but the cheevos didn't unlock) and got the "League 7 legend", now I'll get the leagues 6/5 and switch back to my old carreer.
So, for anyone with this problem, you can try a clean OS install, I'm not sure if it'll work for everyone, but it's an option.
PS.: Sorry for my bad english, it's not my natural language.
GT - rogermacarios