Install "lrmi" using you paketmanager.
After that you can get a list of all available resolutions supported by your graphichardware by using: "vbetest" in a console that already uses framebuffer.
You get a list similar to this one:
 1440x900 (256 color palette)
 1440x900 (8:8:8)
Note the number before your preferred resolution (357 in my example).
Add 512 to this number (357 + 512 = 869).
After that open /boot/grub/menu.lst and change the line from your kernel from something like this:
kernel /boot/vmlinuz26 root=/dev/sda8 ro
kernel /boot/vmlinuz26 root=/dev/sda8 ro vga=869
Thats it. After restarting your system you get the new resolution in your console session.