My multiboot system only boots the first OS
 

I have ten different linux distributions on one drive; it has been working fine, but suddenly, when the menu appears, as soon as I hit any key, the first OS boots. I updated grub and it found all of the oses but it still automatically selects the first one. I would really appreciate help with this. Thanks.

Which distro is the one that is booting and what other distros are installed?

I have two thoughts based on a little bit of experience with dual booting:

Please post the contents of you Grub configuration file. Depending on whether it's Grub legacy or Grub 2, it's likely either /boot/grub/menu.lst or /boot/grub/grub.cfg.

You may need to boot to a Live CD and look at several of the Linux installs to determine which Grub config file is the one actually governing your boot sequence.