Qt Creator auto completion problem

Hi,

I'm new to Qt and I've managed to set up a development environment for Qt Embedded under Ubuntu through Virtual Box.
Now I'm trying some sample code under Qt Creator, and everything compile well, and I can test my application under qvfb.

Well, but the problem is the auto completion that does not show the Qt classes when I'm editing.
I can see my own classes, functions, ... but not those from Qt.

I installed Qt Creator from the Linux binaries, and I use Qt Embedded 4.6.3.
I tried the Qt SDK under Windows, and the auto completion works well without any setup.

How can I fix that ?

Thanks

To illustrate my problem, here's a screenshot from Qt Creator.
As you can see, my own classes are known whereas Qt's aren't.
The standard C/C++ classes and types are well recognized.

Thanks a lot.