OS Error on Boot

[Wade Smart]

20090708 1939 GMT-5

I need a bit more help.

/sdb1 /boot
/sdb3 /
/sdb2 - unused
/sdb6 / home 48gb
/sdb5 /swap

/sda1 /media/disk -backup drive
/sda3 extended
/sda5 /swap

So, my main drive, a 200gb Maxtor is the one that is apparently had it.

I pulled the dvd drive and put in another hd to backup my /home to.
Now the system wont boot. I checked the bios for the ide sequence and
only one drive, the maxtor shows up. So I checked the cables, the
power, still nothing. I put back in the dvd drive and now my /sda1
drive is showing as well as my dvd player.  I thought it was the
cables but... apparently that drive has to be there. Why?

Wade