After upgrading my OS X to 10.8, I can't run or install Lion Server 10.7! Any suggestions?

Hi guys,

My MacMini has automatically updated to OS X Lion 10.8.

I kinda want to re-install my earlier bought version of Lion Server 10.7, but it wont allow me to do so since im now running OS X 10.8.

Do I have to buy the new Server X version or is there a way around it?

Could it be possible to go back to OS X 10.7 somehow instead?

Thanks for your help.