I believe you need to specify the the root device.

Inside the kernel arguments box try:

or 15

If that doesn't work replace 14 with numbers starting at 1 until it does work. You should get the same error you are currently getting even with an incorrect number. If you get something about a file system check failing and it drops to a root shell add a space after hda14 and add "fastboot" like this:

Hopefully I'm not too late :I