2003 Renault Megane car hesitates when moving off from stat

Hi hope someone can shed some light, my car hesitates when moving off from stationary, It moves the pulls back and when you give it move gas it jerks forwards after that its ok in all other gears. it does this when in the first gear and try to move off. I have had it checked by renault they said they rest the computer, then it was ok for a while now its doing it again, aaarrgh.

thanks in advance

Raj