I guess you're using Opera Mobile (native, available in repos, full version), and not Opera Mini (J2ME, needs IcedTea+microemulator) -- Both work on N900.
I'd advice changing the title so not to confuse others

If microB is not working either, I guess it's a local connectivity issue? (or are you saying microB connects to google?) Are you connecting over WiFI or cellular?
Switch connection and try again.
From terminal, try sudo ping www.yahoo.com
Or check if other apps like rss reader still work?
Reboot?