Right have taken it out and played around with it.

 

 

From cold in 2 gear having just come round a corner up onto a slight hill and put the foot down not excessively as its still cold. Was just about to change up into 3 but before i could do it the car bogged. I snatched 3rd and it went nicely again. T

 

 

Later car nice and warm at it accerated nicely in each gear whether I treated it gently or pushed it. No more signs of bogging out.

Good luck :)

 

My car bogs a bit when cold too but I have put it down to all the mods I have done :)

 

Let me know if you find anything definitive

 

Cheers (free bump)

Any particular rev limit at which this happens ?

Have you checked the connection to the temp sensor ?

Right for those with the same problem i found this link

 

http://zhome.com/ZCMnL/PICS/hesitation/hesitation.html