I've tried using Skype as an IM service on my N900 for daily messaging, and find the phone frequently "believed" it was logged into Skype, but in actuality it had become disconnected. Messages would get "eaten" when I tried to send them. I'd get a "messaging not authorised" error and everything I typed would get lost - and I'd have to disconnect from Skype and reconnect again before I could send/receive, sometimes multiple times before I could successfully send. Or messages wouldn't be received for up to a week (or never) at the other end (which was usually my husband on another N900, and experiencing the same problems). Not terribly useful when I was trying to organise the timing for when I'd need picking up at the railway station coming home from work each night.

We started using Ovi Contacts/chat instead - at least when that said you were online, you usually were. Unfortunately, Nokia are pulling support for that away from the N900, so we're losing that as an option.

Does anyone have any recommendations for what service to look at to provide IM that integrates nicely with the N900 contacts, and is more reliable in actually staying logged in/relogging in properly when the phone service drops out momentarily? Or any solutions to fixing Skype so that it actually works?

Each sms costs 25c to send (and can have a 20 minute delay if I send it during the normal segment of the train trip home), whereas mobile data is 1.5c per Mb - so IM is a much preferable method of communication...provided we can get it working reliably. We're not unwilling to sign up for a new IM service - I just don't want to have to sign up for 10 of them just to find one that works for us when other people have probably already been through similar reliability testing.