Tried single mode? And also there is another way. Boot your box with a Knoppix or another CD-Based distro and mount your Linare root partition under some directory. After that edit the /etc/shadow file and clear the password field of root like this:
Code:
root:MyEnCrYpTeDPaSsWoRd:12304:0:99999:7:::
becomes
Code:
root::12304:0:99999:7:::
then you'll be able to login as root with an empty password. It worked many times when i forgot the root password :-P