I'm using Inkscape for a while now and have to say that i really like it.
Out of nothing i can't draw any rectangles and stars any more, they're there but not visible. If I try to select them it won't work and I can only move them with the arrow keys.
I'm using Ubuntu 12.04 the problem occurred with inkscape 0.48.3, I "merged"this version and I'm now using the trunk version but with the same problem.

I've made a screencast to illustrate the problem.
Please have a look en tell me what I'm doing wrong?

http://youtu.be/sTWXPnMIWiI

The opacity of your object is 0. At the bottom left corner of the screen where you see your object colours, there is a small text field labelled "O:". It's zero in your video. Change it to 100.

How stupid of me, I've been looking it over and over again

Your my hero of the day!