Record Kontakt drums in Cubase

I’m finally getting results with Cubase 6— I’m thick, Cubase is fine — in a file with three working tracks, Cubase Synth, Ominsphere guitar, and Kontakt 4 Piano all work. I’m using a midi keyboard. I am also using Kontakt drum kit, getting different percussion instruments & simple drum grooves when I play a key, but that will not record. The other three work fine. Am I going about this the wrong way? I’m mostly improvising, but I’d like to lay down some sort of a drum track to start with. What am I missing?



Windows 7 Professional
Service Pack 1
Intel® Core™2 Quad CPU Q6600@2.4GHz 2.39 GHZ
4.00 GB RAM