Dvd tray will not eject GSA 4040B

My dvd burner GSA 4040B will not eject the media and requires 4 or 5 oporations of the eject button before the draw will open, this occurs even with just power to the drive (no ide connection). when the eject button is pressed the tray gives a clunk, the light flashes several times and then stops.
I also have the same problem with a GCE 8525B CDr/RW in another computer which has a GSA 4060 fitted that works fine.