Thanks Knotted. Yes that's what I was thinking, but since it only happened once I wondered if it were just the circumstances under which I was shifting or was it more cable stretch, or a combination of both? I have adjusted this very limit screw on day 2 of owning the bike when I dropped the chain 3/4 times shifting from small to large chainring! Mind you this was a brand new bike at that time, so you can imagine I was p*ssed! They should have more thoroughly checked things out before letting me walk out with it.
Anyway, thanks for your quick reply.