tty1 default display also when in init 5

["Gianluca Cecchi" <gianluca cecchi gmail com>]

Hello,
my fc6 system boots in init 5 as default.
I noticed sometimes that at the end of startup process, what displayed
is the tty1 window, not the graphical one. Infact if I log in and
digit "tty", I get tty1.
If I press Alt+F7 I get the graphical login page.
I have not the PC here now, but as I'm writing I'm reminding that two
days ago, during normal operation, I switched to init 3 and then I did
a shutdown of the PC from init 3. Probably since that moment, when I
boot I get the terminal window...
This evening I will try to reproduce this, but before I have to reget
the default graphical behaviour... Can anyone try?
Otherwise, how can I debug this?
Thanks,
Gianluca