I recently installed Arch Linux on a USB hard drive with disk encryption via dm_crypt. Everything is working fine on the system I set everything up on (my laptop) but when I try to boot to it from my desktop it does not work properly: it boots up fine, finds GRUB and allows me to make a selection, etc. but after I make my selection and it begins loading the OS the keyboard stops responding (no text entry, cannot toggle lock keys, but the cursor on-screen continues to blink) and thus I am unable to enter the dm_crypt password and finish booting.
How can I make the keyboard work/be detected properly? Is a standard USB keyboard.