you let up on the clutch before the car was going fast enough to enguage into the gear.
usually when backing out of a driveway... (well except my own, caus it steep enough to let the car roll down) i keep the clutch 1/2 depressed, and ready to push it down if i feel any "fluttering" of the engine, while depressing the gas.
ah, ok. a fun thing to do. get on a flat surface (prefferably an empty parking lot), put the car into 1st gear, and SLOWLY, ever so slowly lift up on the clutch. i'm sure you know the car will eventually start to roll, because it's begining to enguage itself into gear, and the engine IS running (at low rpm's, so it doesnt go very fast). now, just take note as to where it starts to flutter, and ultimately, stall. rougly, just before that is where you want to keep the clutch depressed when stopped, and when trying to move slowly (like backing out of a parking space/driveway, parallel parking, inching up in heavy traffic
oh, and why do you start the car in 2nd gear? unless you've got a power demon and you're trying to get moving on ice, why is 2nd better then 1st?