Hope this helps... it doesn't seem to be written down anywhere.

This is pretty much what I've been trying to sort out for a couple of days (to talk to my wife's phone). Short answer seems to be: it's broken.

Nokia used to used to use XMPP/Jabber-style chat. They switched Ovi chat (and mail) to Yahoo-powered last year.

There has been no update for the n900, so it's looking at the XMPP network. The new phones will be looking on the yahoo one.

Confusingly, everyone seems to get accounts in both networks (with the same username/email and password) so you can both be signed in and not see each other.

So if the other phone can (easily) do jabber/xmpp (or they have a google account) you can sort out a connection to each other through that.

I installed the Pidgin protocols plugin for Conversations and Contacts.

I've been trying to sign in as a yahoo IM account with my ovi email and password (note those details seem work for the yahoo website - but seem to stall the login on the messenger for web).

I haven't succeeded - on the n900 or a couple of open source chat clients. There might be some way of setting it up in the advanced settings but nobody seems to be saying if there is.

I will try one last tweet to @ovihelps about this, but in the mean time I've just made a new yahoo account (which it's said I should be able to connect to the other phone with), and signed in successfully. (Haven't tried connecting to the other phone yet...)

That's certainly not a fix.

[Also - for me, it seems the first time you make a yahoo account with the Pidgin protocols, it will result in a 'not signed in' message unless - when you're making the account you go into the Advanced settings and delete the first web address ('server') you see]