I ran into the same issue and did some digging. It appears that, somewhere along the way, the functionality changed, so the package that you downloaded (I'm guessing it's the "AudioInsecure" package) doesn't work with newer versions. However, it may work with an older version.
I found Loader.v3.8b for Dummies.v2.zip and that works for it. AudioInsecure is included with it, so it can be enabled via the hidden mod tab (hover the cursor on the right side of the screen, about an inch above the bottom to reveal the tab). Adding another, similar, package should be possible by adding a line to the Mods/Mods.txt file. (Base it on the AudioInsecure line.)
Unfortunately, I didn't save the link to that particular loader and a quick search on the boards didn't turn up a link. It seems to appear on a lot of torrent sites (standard cautions apply).
Best of luck.