There was than mod that allow custome races to get than gentic insuilt from the Dark Elf Pirsoner at the start of the game so the empour party will start to move to show up in your cell.

http://www.tesnexus.com/downloads/file.php?id=1815

Also there is a an OBSE command "setracealias " that can be used to bypass that problem. It makes the prisoner, and everyone else, think your character belongs into one of the default races the game has, but has to be done everytime the game is started.

The Unofficial Oblivion Patch makes the custom race fix obsolete, I thought... I would try the console command if the UOP is not working for you. There is no reason to waste a plugin slot, and you should definitely NOT drop the UOP.

Thanks for the help I like the mod route as I donot use too many mods anyway.

Did you have the UOP already?