How to Step Record Midi in PT LE 7.4

[sirprotools]

I am trying to step record midi in PT as you would with a drum maching. I have it on loop playback, with the midi instrument track armed. Whenever I go to pencil in a beat, the loop stops and the penciled beat is a mile long.

Can it be set up so that you just drop beats in as it loops with midi merge, so you can layer up drum sounds (like in the old days, or in cakewalk for example)?

Can't seem to find a way in the manual (which I read pretty carefully). Seems to require a midi controller to do it.

[sirprotools]

Ah, never mind, figured it out. Had to unlink timeline and edit selection. Still cant drag midi info from Superior Drummer 2 without ovewriting midi info in selected loop though, so if anyone has a tip for that, would be cool.