Sorry, I don't have an answer, but thought you might be interested to know that I have had 3 new ovens with the same symptoms. The first 2 were hotpoint and the 3rd a Canon. We are awaiting replacement now. Sounds like a hotpoint/canon component fault - thermocouple perhaps.
Chris
June 2008
Automatic Answer
While you wait for answers, we may have found some information which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix gas cookers.