I deleted 'splash vga=791' ,then when I hit Ctrl+Alt+F2~F6, I am sent to virtual terminal,
as to F1, it says could not load deb /lib/modules/2.6.31.4/modules.dep :
No such file or directory ..bla bla....

I did some frame buffer programming in my Ubuntu i386. I did the some work to enable frame buffer in Ubuntu i386.
Here is my note on how I got it.
==========================
$ sudo vi /etc/initramfs-tools/modules
65 add he following three lines
66 fbcon
67 vesafb
68 vga16fb
69 $ sudo vi /etc/modprobe.d/blacklist-framebuffer.conf
70 make it look like this
71 #blacklist vesafb
72 #blacklist vga16fb
73 $ sudo vi /boot/grub/grub.cfg
74 add vga=791 (means 1024*768,16bit) behind the linux or kernel
75 $ sudo update-initramfs -u
76 $ sudo reboot
77 To do framebuffer programming without being root,add yourself to video group .
78 $ sudo adduser <username> video
79 And log out and login again.
80 $ groups
81 see what group you are in
82 You can program now
==========================

I tried the same thing in Ubuntu amd64 with the right kernel, it works.
As to the kernel complied by myself, I will check later.
I guess there would be no problem.