How to start XFCE v4.2 RC3 once installed over 4.06

[jan]

Hi there,

I installed Xfce v4.2 RC3 (using grafical interface -
xfce4-4.2RC3-installer.bin on Gentoo). 

My problem is: 
When I use "startxfce4" or "xfce4-session" command I get my previous
desktop with Xfce v4.06 (Old Xfce Setting manager, old panel, and so on
...)

Did I do something wrong ? Installation completed succesfully.

Thanks
Jan