Hi
It might be due to you'r grafic ain't compatible with Linux....
But you can install in text mode, when you boot from the cdrom, instead of just pressing enter to install type in: text to make Linux install in textmode...
The /sbin/loader as to the best of my knowledge looks for external perphials such as mouse and keyboard, so perhaps it could also be your mouse causing the problem (Im am not sure about so don't take my word for it (just guessing)) :-)
But at first try to find out, if you'r grafic device is supported by Redhat, you can find a list of supported devices on redhats homepage
http://www.redhat.com
Peace Torp