I think the core of RTComm for Maemo4 is basically dead. Thank goodness they used the purple lib though.

Now... (I think) you can force the update via:

apt-get install libpurple0 - The latest version is libpurple0 (2.6.6-0nix1)

I'm not sure if apt-get install or apt-get upgrade will work here, but that should get you closer.

Or it might be (explicitly) apt-get install libpurple0=2.6.6-0nix1 but I think that method you will miss out on some of the dependent libraries that also need updating.

You can check which version of libpurple you have via:

apt-cache policy libpurple0

And you'll see if there are any updates available - have your app catalogs all enabled.

<edit> I knew my bookmarks would come in handy one day - this thread qole was going in pretty deep about the commands and the problems last year. I forgot that MSN needs telepathy butterfly, among other issues.