SLES10-SP1 tty1 not working

[sloschimoschi]

i have the following problem with SLES10-SP1 with XEN installed (and booted):

the first console (tty1) isn't working, i can't log in:
when i press any key, i don't see the character I entered.
when I press enter, i get the message "welcome to suse linux enterprise server... hostname login:" again and again.

all other consoles (tty2+) are working well