Firefox display problem gatein portal

[akayen]

Hi GateIn-Community,

I am doing a project with Convertigo and I use the portal GateIn to make my widgets.
I used the containers "tabs" to create my widgets.
All went well until I point a web browser used to view my page.
My problem is that when I use firefox 5.0 the first tab is displayed correctly but if I go to the next tab page appears in half.
With Internet Explorer the problem is that gatein does not support style sheets, but my tabs working properly.
Attached is a picture that sums up the display of my page.
I'm really annoyed and I'd like to find a solution to continue to progress.
Thank you in advance