I have figured this out, so for others who face the same issue.
IDER doesn't quite live up to some of the hype. Unlike the remote control which is 100% hardware - no requirements on the OS. IDE redirection to remotley mount a CD is.
When you boot the system, the BIOS understands about redirected CDs so can boot the system. But the redirected CD does not appear as a standard IDE interface to any host OS. So when teh OS takes over from teh BIOS and needs to understand about the CD (for example during an install) it needs a driver.
Windows has had a driver for some time, but it apparently didn't reach the main stream kernel until 2.6.38 - and then the distributer of any distrib needs to ensure it is enabled.
Very few Linux distributions at the moment have this support built in.
My answer is to buy a cheap USB key, have a linux boot enviroment installed on that and keep it with it.
A little disappointing:)