that doesnt sound like a clutch issue to me.. at least not a physical one. if the clutch were mechanically flawed it would happen almost all the time and in reverse as well...
i first assumed maybe you were in 3rd, but seeing as that several people are expericing this i now doubt it lol. but, is everyone sure it was 1st gear??? sounds a hell of alot like what would happen if trying to get moving in a higher forward gear