Why is my machine not showing anything when booting?

I'm using Ubuntu Server 11.10 x86, and after I make my normal selection (Ubuntu, with Linux 3.0.0-12-generic-pae) from the GRUB menu, the screen just goes blank - there's not even a cursor showing up.

Basically I (suspect that I) had a bad NFS mount tying up the boot process so I fixed that and now it seems like the boot is actually worse off. Here's the problem I had before: Is a bad NFS mount preventing a clean boot?

Not sure if this is useful, but when I hit the 'e' key in the GRUB menu, this is the configuration that shows up:

setparams 'Ubuntu, with Linux 3.0.0-12-generic-pae'

recordfail
set gfxpayload=$linux_gfx_mode
insmod gzio
insmod part_msdos
insmod ext2
set root='(hd0, msdos2)'
search --no-floppy --fs-uuid --set=root <long hex value>
linux /vmlinuz-3.0.0-12-generic-pae root=UUID=<another long hex value> ro
initrd /initrd.img-3.0.0-12-generic-pae

Recovery mode works just fine, networking and all. In fact, if select recovery mode it actually brings up the following menu:

Recover Menu (limited read-only menu)
  resume - Resume normal boot
  fsck - Check all file systems (will exit read-only mode)
  remount - Remount / read/write and mount all other file systems
  root - Drop to root shell prompt

and if I select resume I get the following output:

<timestamp> tpm_tis 00:00: tpm_transmit: tpm_send: error 4294967234
initctl:Event failed

Ubuntu 11.10 <server> tty1
<server> login:

Everything works fine after that.

Other things I've noticed: 1) when booting normally, the Num Lock and Scroll Lock lights on they keyboard show (after pressing the corresponding keys), but the Caps Lock doesn't 2) Ctrl+Alt+Fx to switch TTY's doesn't work 3) this link doesn't help at all: https://wiki.ubuntu.com/X/Troubleshooting/BlankScreen

So, back to the original question: why is my machine not showing anything when booting (in non-recovery mode)?

Not sure why this would all of a sudden be a problem but whenever I have this problem adding "nomodeset" to the end of the linux kernel line fixes it. Try editing the grub boot commmands (press e at the boot menu) then edit the kernel line so it looks something like the following then press ctrl-x to boot it.

linux /vmlinuz-3.0.0-12-generic-pae root=UUID=long-hex-value ro nomodeset

If that doesn't work, you know that it's probably something to do with your grub boot options since recovery mode works but normal mode doesn't. I would just compare your recovery boot options to the default and try to figure out which option (or lack of) is causing it to work in recovery mode.