I'm not sure from your description, but perhaps you're having a
general problem with Domain Name Server (DNS) lookup. In that case,
put a check mark in 'Synchronous DNS' on the Advanced Preferences
dialog in Opera.
If that doesn't work, try http://209.100.136.246/
instead of http://www.operasoftware.com/
I've seen a few cases where my Internet Service Provider's DNS has
somehow gotten the wrong IP (numerical) address for a domain name,
with the result that the site can't be reached by name.
Domain Name Servers are supposed to update automatically so it's
unlikely that such an error would remain for months, but it's worth a
try.
--
Joe