We have added a new domain suggestion tool. You can enter some keywords, and the tool will generate a list of possible domain names that are related to your keywords.
You're right... this is the second problem like this I've found with Windows Vista. Something similar was happening on one of my own sites. If I use firefox on windows xp there isn't a problem.
It's actually surprisingly useful. One bug you may or may not have noticed is that if you enter something in the suggestion box then press enter rather than actually click the suggest button it doesn't return any results. The search for domains page is the same. Or is it just my machine playing up? It's only a small issue anyway.