We had the same problems with four year old daughter.  No matter what we tried--normal routine, bath, etc, nothing would work. She  would not want to get up in the morning and it effected her temperment.  We saw a child psychiatrist who decided to put her on clonidine.  We give it to her before dinner and she is usually to sleep by 8:30. We have lower the dosage by half and hope to ween her off it.

Our daughter is also gifted and even w/o naps would be awake some nights until midnight.
Good luck

Have you asked him how he feels this problem can be solved?  I know with my son he can come up with a zillion different reasons why he won't do this or that, but if I present it to him as a problem and let him figure out the solution he comes up with the right solution.  

If he really is scared, would a night light help?  Playing Mozart softly has been shown to help kids go to sleep.  Does he have a favorite stuffed animial he could sleep with?  

Do you follow the same routine every night?  This helps a lot.  Try not to let him get overstimulated before bedtime.  Our routine is bath, sit outside on the porch and talk and listen to the "night creatures", read a story, say our prayers, then lights out.  You will need to start about an hour before bedtime to get the calming effect.

Don't let him eat too much sugar, especially in the evenings.  Limit sodas (definately no caffiene) and juices.  Make sure he eats a snack after dinner so his tummy will be full.  

If all of this fails, try using 1/2 a 3 mg melationin tablet given an hour before bedtime.  Only use this short term but it will help to establish his sleep patterns.  I have used Calms Forte also with good success.  My 6 year old sleeps 10 - 11 hours per night once we got a routine going and established a good sleep pattern.

Dear Kathy,

A child of your son's age should be getting about eleven hours of sleep. He is going to be too late.

To solve this, you'll need to bite the bullet and be prepared for some tough sledding, though this is happening now anyway. Have you read Solve Your Child's Sleep Problems by Richard Ferber? The technique will be effective, but it depends almost solely on the parents' willingness to adhere to the regimen.

I won't go into details here, because you can read it in the book. But you can utilize the SEARCH function in this Forum and you'll see replies to questions similar to yours.

Rest assured this can get better. But your son has learned some unproductive patterns which will now have to be interrupted. But if you're determined and confident, it'll be OK.