Inconsistent Search Results

[Vista HP, with UNC path add-in to allow indexing of UNC paths]

Any ideas what's wrong or how to fix it?

I do a search from the Start button - up come all the files I would expect
to find the keyword in (in indexed locations), including MS Word 2002 docs
(and I note, in the words docs inside ZIP files... I'm sure indexing didn't
work like that before!)

Use Search from the Start menu and I get the same (good) results.

But - open a folder which contains all the known files containing the
keyword on the mapped drive/UNC path and search for the same keyword - using
only the ordinary search box (not advanced) - ie searching only the indexed
locations that I know from above ARE indexed - and it doesn't find any files
at all.

Eh?

Julian