My site has a home page title something like "All about widgets"
Pages have individual titles: "Red widgets"
If you search Bing/Yahoo for "Red gadgets"
The link in the SERPS reads:
"Red widgets - All about widgets"
It even repeats a word, as widgets is repeated above. It adds the home page title to every page that I have checked.
Not hugely significant, except I feel it makes my site look less clean in the SERPS