With reference to this post I finally figured out that I could after all use a Linux softphone with our iptelephony solution at work.
At first I tried Ekiga, since it’s Ubuntu’s default softphone app, but it didn’t really work, kept on hanging.
I tried Twinkle, which worked right out of the box, but using QT 3.x libs ? I just couldn’t settle with that. I don’t like to mix QT libs in my glibs environment and I REALLY don’t like to use really old QT libs if I must have them.
I took an other shot at Ekiga, and dug up this post at launchpad which solved my problems.
Upgrade to Ekiga 3.2.6 and things should be okay with Karmic, pulseaudio and Ekiga again.
Launchpad Ekiga 3.2.6 repo here.