"Startup Disk Almost Full" But 190gb Free?

So I recently downloaded a program (MCMap Live) to make an image of my Minecraft world.

I ran it the first time and it took up all my RAM like expected, but gave me issues.

So I try to run it again without any other programs besides Finder running and my Mac started puking out this error that my startup disk was almost full and I had to kill some apps or delete files.

I open Finder and it tells me I have over 190gb of free space...

I ignored the warning and after the program was finished and I restarted, my airport card stopped working. So I restart again.

The airport card turns back on, but now I can't run any intensive programs because that error about my startup disk keeps coming back and shutting them down.

Does anyone know what is going on and how to fix it?

MacBook Pro Late 2008

2.53GHz

4G Ram

320 Gb Hard Drive

Snow Leopard 10.6.8

Thanks in advance.