Hard Drive Is There, Then It Isn't


I have a G4 500 TiBook currently running 10.3.9 and I wanted to install Tiger on it. The issue I am having is that when Tiger restarts my machine to install, it says it cannot due to the fact that it cannot find an install of 10.3. It seems that when my machine goes through the "restart" it has a problem locating the OS and the hard drive. This also happens if I have to restart due to a program update or something along those lines. When the machine boots up, I get the gray screen with a folder and question mark.

This DOES NOT happen whenever I "shutdown" and power back up. I tried resetting the PRAM and that did not change anything.

Anyone have any ideas?

Thanks in advance....