Reply to Lag with my MIDI keyboard (Ableton Live)

Hi,

I'm learning production, and I face a problem that really blocks my creativity.
There is a latency between the moment when I hit the key and when I can hear the note.
It makes it really hard to play a synth or whatever on the beat that's going, and I have to go back and edit all the notes that I recorded, it's annoying as hell.

It only happens in Ableton Live, because for example if I run Massive in standalone version, it's fine, and response time is perfect.

I've been told it's related to the latency of the soundcard, but mine is like 256ms so it's not a big deal ?
It can also be related to my PC being not powerful enough, but the charge seems low, and my CPU is an i5 2500k @ 3.3Ghz (gaming is the first purpose of this computer).

My MIDI keyboard is a Novation 49 SL MkII, hooked via USB, and my soundcard is a M-Audio Fast Track.


I don't get it, it must be related to Live or something but I would really appreciate if you could help me on this one.
Thanks.