I'd rate the S10's propensity to roll forward off the sidestand about average. It does over-center a bit, but not a lot. (Mfgs don't like to have sidestands that over center a great deal because it can keep the bike from turning if the owner defeats the sidestand interlock and rides away with the stand down.)
Over the years, I've developed a healthy distrust for sidestands. Sloped and off-chamber surfaces are killers. I'll spend a lot of time moving the bike around to find the angle and orientation where it is the most stable and if I can't find something stable, I park elsewhere. If the surface is not dead level or pointing uphill, I leave the bike in gear and preload it against engine compression before leaning against the stand. Sometimes the center stand is a better bet. As I get off, I hold the brake as long as possible and pull the bike towards me and confirm its stability before letting go. If it doesn't seem stable or is too vertical, I remount and move it.
I think the best habit to prevent parking lot drops is to always rest the bike on the sidestand while dismounting. Most of the stationary drops I've seen are yahoos trying to dismount while keeping the bike balanced vertically, typically because they are planning to roll the bike somewhere after dismounting or use the centerstand.
- Mark
). Anything I can do to prevent a parking lot/gas station nap... where I Have had to pick up less heavy machines b4... ??? you know. 
