Unable to Launch Client

This may end up being a long post, so my apologies in advance.

For some time now, I have been unable to run the FCS (1.1.1) client on my laptop. It started after I updated to OS 10.5.7. I would double click on the application icon, and it would begin to open in my dock, and then close after a few seconds. I did some searching on the internet and decided to try reinstalling the client. I did this by removing the application file and any reference to it (plist and library files) as well as opening the Java preferences and deleting the cached files. Then I went to my server's web page and downloaded the jnlp file again.
At this point, the situation became worse, because I couldn't even run the jnlp file to install the app. When safari opens the file automatically after download (or if I double click on it manually), nothing happens. I looked in the console, and no errors are reported. If I open the Activity Monitor and watch it, I can see a process called javaws start up and run for about 20 seconds or so, and then it quits. Again, no related messages in the Console.
Several forums online suggested using Java Preferences to remove the cached files and then re-associate jnlp files with the Java Web Start.app file located in the CoreServices folder.
This did not help.
Another forum suggested reinstalling the Java for OS 10.5 update 4 (and later update 5).
This also had no effect. I'm at my wit's end here. If anybody can offer some suggestions, that would be great. Here is some relevant info:
My Computer:
MacBookPro, 2.33 Ghz Core 2 Duo, 3GB RAM, OS 10.5.8
Server:
MacPro, 2 X 2.66 GHz Dual-Core Xeon, 4 GB RAM, OS 10.5.5
Final Cut Server 1.1.1
I have several MacPros running OS 10.5.6 that my editing team uses, and they are all able to run FCS just fine.

Please Help!

-Drew