@ ichobi
Hrm. I've found the problem - several of the libraries that are required for MPlayer to run (the custom version) are installed in a rather esoteric location on the hard drive - specifically in the middle of the darwinports section. Now, that said, I've put together an installer that does install them, in the correct location, and works perfectly well - the two machines I had been testing on had actually both been used in my compiling stages, so both had the support. I deleted the relevant files off one, tested my new package, and both the binary and the libs install and function correctly. The new package unfortunately has to create a new directory on the root level of your hard drive (/opt/), but that appears to be unavoidable - and it can be made invisible easily enough, if it's an irritant.
Anyway, I'll upload the new build as soon as I can - my server's currently being a pain in regards to FTP access, and is therefore... not currently working. Which is irritating. That said, as soon as it's done I'll post here. Won't be too long
-Andiyar