Do you have access to an external firewire hard drive? I have installed Leopard (clean install) on an external drive and copied all my settings, applications etc. to it. Here is a link on how to install Leopard on a firewire drive:
http://www.macfixit.com/article.php?story=20071025100548752
I am booting to this drive while I wait for the replacement MBP which is coming from Apple. One has to deactivate Adobe products and deauthorized iTunes then activate and authorize when booted from the external drive. I have access to another Mac. An external hard drive might give you the following options:
1. If software related, the issue might disappear when booted from the external drive. Once satisfied all is well with the external drive and the functioning of your software, you could do a clean install on your internal drive and copy all settings & applications back to it. I find it is better to go the "clean install route" rather than try to clone a Leopard hard drive. I have had mixed success with cloning since Leopard came out.
2. If you have access to another Mac, you can boot to this external drive and continue your work while you wait for yours to be repaired. The external drive will at least function as a backup of all your work and applications before sending your computer off. It can then serve as your Time Machine when your computer is returned.