They have explained about the search restrictions on the site on the blog (
http://blog.1911census.co.uk:
'Wildcards and other fuzzy search features
December 20th, 2008
A lot of people have fed back that searching the census is not as flexible as it could be! There’s a good reason for that - at the moment some search functions are deliberately restricted. This is to allow the site to deal with more queries immediately after it goes online in 2009, when it is expected that there will be huge demand from people trying to access the service.
The majority of people will be able to find at least some of their ancestors with the current search options. However, as soon as the demand has stabilised, we will release updates to the site to turn on searching with wildcards (including an initial wildcard), provide NameThesaurus variants, and will also lift the restriction that requires users to use a surname for a person search or a street name for the address search. When these restrictions are relaxed it will be *much* easier to find the more elusive ancestors.
Sorry we can’t open these up to you for the moment - however, we need to test the site as it will be at launch. We will email everybody who is registered on the site the moment new features become available after launch, so make sure you register.'
So it looks as though we'll have to wait a while for more complex searching.
Cheers,
Tewin