DivX Player + sound issues

I installed DivX 7 along with an audio codec (as there was no sound when I tried to watch the movie at the beggining). Everything worked properly after that and I did all these having headphones plugged in.

The next day when I removed the headphones I realised that there was no sound from the laptop's speakers anymore but only if I had the headphones plugged in!!

I unistalled both DivX and audio codec and the problem still there!!Everything started since these downloads took place - so I was wondering whether the download of the software has anything to do with the problematic (now) sound of my PC.