I have the same problem with my hotpoint aquarius and havent found a solution after 5 years of owning it. I thought it was something I was doing in the first year so didnt call out the engineer. However, nothing has helped. Running it on a hot cycle will only stop the smell for a wash or two and then it returns. No idea why but googling this issue shows it is a fault with this particular machine.
Now I simply put the clothes on a rinse cycle after the normal wash. Annoying but at least it helps.
Belle, May 2012