I've encountered this problem exactly one year ago, and now it came back.
So it's like this: when I engage first gear into second, second into third, third to fourth or fourth to fifth, the gear pedal remains up, it doesn't come down to it's original position, making the next shifting up impossible. Last year I fixed this problem by adjusting the clutch cable (tightening that free play, to be more specific).
About 4 days ago, when I was in vacation in Bulgaria, about 400 miles away from home, the problem reappeared. A tightened the clutch cable again (it wasn't loose much), but that didn't fix the issue.
What I do now after each and every shifting up is slowly push the gear pedal down. No problem when easy riding, but when pushing hard (especially when also cornering) it's an operation that eats time and attention, and it's quite disturbing.
Has anyone had this problem? I will go to the doctor if necessary, but maybe it is something that can be fixed easily.
Thanks a lot!