quicksilver and leapord problem

I would download a different version of Leopard Assist or perhaps download a new copy for a different source.

It worked the first time on my old Dual 533 G4.

 

Firstly, I found that regardless of what others told me, Leopard increases performance in many ways over Tiger with that much RAM installed.

Secondly, go to System Preferences>Startup Disk and highlight the hard drive you wish to boot from. The next time you start up, it should automatically choose that disk.

 

LeopardAssist does not change your clock speed. It only changes what the system sees you clock speed as. Roughly equivalent to changing the numbers displayed on a speedometer to show you going 100 instead of 80.

 

If anything, it changed the way your clock-speed is reported in order to "fool" Leopard into believing your hardware can support it. It should have reverted immediately after installing, but it would seem it hasn't.

I'd just do an Open Firmware reset.

With the computer off, press the power button. Immediately press and hold Command+Option+O+F and release it once a white screen of text appears.

Type reset-nvram and press return/enter.
Type reset-all and press return/enter.

The Mac should restart and all your settings should be restored.