Okay just a few things/thoughts/suggestions:
I know you said don't suggest dream spinning but have you tried other dream stablising techniques (looking at hands etc. rubbing hands?
Also, do you realise that your dream is fading or do you just wake up?
Another thing, have you read the thread about linking lucids/dream chaining? Its called DEILD I think. The basic idea is that you keep still with your eyes closed as soon as your lucid finishes and soon enough you will be back in another dream.
And finally, how many lucids have you had? Maybe your body will get used to the experience of getting lucid and the excitement will wear off allowing you to stay asleep.
Good luck,
Ellie
(feel free to PM me if needed )