Pressure plates, frictions, or baskets usually cause clutch drag. It's pretty normal for a bike to stall as you drop it in gear if you don't give it a rev first, especially when cold. Don't go throwing money at new clutch parts. If the clutch application is jerky or you can feel the bike trying to creep forward with the clutch in and in gear, then it's time to be suspicious of the clutch. The couple of brand new bikes I have ridden (a couple of 03 WR's back in 03) all died when you dropped them in gear without revving. In fact, the only bikes that don't do it that I have ridden are my TT225 and a XR650L.
All this said, always check your clutch lever freeplay. Sometimes, I even have to adjust it while I'm riding. Too much play will make the clutch not release all of the way and cause these symptoms.