[G4] What Have I Done To Deserve This

[Umar Stone]

G'day everyone, I have G4 Quicksilver audio mac, which I think is  
great,.. sometimes.
Basically a 1.2 GHz, 2MB L3 cache, 1.25 GB SDRAM, a while back (2007)  
I put a second internal drive in a 301.7 GB Maxtor 3200, and also  
have an external drive. Running X10.4.9  and X11
Before I put in the Maxtor the initial drive had been malfunctioning,  
if i clicked the screen with the mouse Finder would restart, and also  
many programs would crash if I chose to save a file.
So I made the Maxtor my Startup, which has been working fine for a  
while, now again Photoshop crashes with saves, same with Flash iTunes  
wont let me authorize my songs and the iPod is not charging, the  
printer won't accept 'print' (it all crashes if i click on a choice)

I've tried the Apple Hardware Test, but the mouse won't move in the  
language screen neither the keyboard, Disk Utility say's it's fine, i  
can't detect any viruses; cleaning the cache doesn't help;
Can you?