Ok well if it is failing (let's just say it is), how do I deal with that? I mean there's nothing I can really do about that right?
I'd try making the jar without compression, just to see if that makes a difference. In Eclipse, one can
choose to have the compression or not. I am not familiar with JarSplice or its settings. But if that is an option, the issue is just fuzzy enough for me that I'd want to test it.
I'd also try and step through the program--you can't do that from the .jar, but you can use Printlines to display contents of variables. In general, nailing down the exact situation (as much "state" as there is) for a difficult bug often exposes faulty assumptions.
Another thing I've done when being frustrated with loading resources: I put a copy of the resource in every dam directory where the URL might find it, as a way to see if I have a misunderstanding of the syntax and how it is interpreting the location. I've been confused before about when to use "/" or not at the head of the address, for example. I usually create a file "audio" and have the sounds there, one level below the calling code.
So sorry to hear this is running afoul of the Ludum Dare deadline. Good luck, I hope you get this working in time! I wish I had some better suggestions.
Another idea, if you have time: make a minimum case example, a program that uses TinySound to load and play a single sound and nothing else, and run it as a jar. It should be short enough to fit in a single class that you can post here.