I've just come back from working away for a few days and the very first AB question I read has a reply which is complimentary to me. That was a nice 'welcome home' message. Thank you, The Prophet.
I'm not sure that I'm quite as 'expert' as has been suggested, but I'll have a go at answering anyway:
My advice is to forget about booking online - just pick up the phone. The first place I'd try would be Deutsche Bahn (UK). They sell tickets on behalf of most European railways and don't charge a booking fee. If they can't help, there's always Rail Europe. They charge a �6 booking fee but that's per booking, not per ticket. There are also several other agencies which could probably provide you with tickets and reservations (but do watch out for hefty booking fees with some of them). Details are here:
http://www.seat61.com/Europe.htm
However, before you completely give up with online booking, you might like to try this website:
http://www.italiarail.co.uk/tickets/IR/IRUK.as p?AFF=ITR
Chris