Lost web connection

This is one of those irritating problems which has, so far, defied any
attempts to reproduce it on purpose, so I'm writing in the hope that the
generalised data I have strike a chord with someone and, hopefully,
elicit an answer. The problem has started only since I began using Vista
(Home Premium).

When surfing with Firefox (my usual browser, but the same applies to
IE7) I occasionally "lose" all connection to the web - any URL produces
a "page not found" error. Switching browsers does not help at this point
- the same error occurs with IE7 too. I can access my mail connection -
just the web refuses to respond (DNS problem?)

My partner's computer (XP home) is on the same net connection via the
same (Netgear) router, and it continues to work normally. I can access
the second computer across the network too - in other words the router
is working OK, and connected to my ISP OK (I can get mail still, as I
said). My ISP doesn't report any random DNS problems but, if that were
the problem, my partner's machine would fail too.

Restarting my computer (and nothing else) restores the connection to the
web (works every time). I suppose the obvious answer is some sort of DNS
problem, but I'm not technical enough to guess what. As it didn't happen
with XP pro on my old machine (same connections) or on my partner's
machine, I'm assuming it's Vista related.

Any ideas where I start to look?

Regards,

Bob

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