Hmm, that's unfortunate. My receiver works fine with Neo 6 on the AC3 tracks, upmixing to surround and keeping the LFE intact, but I guess it depends a lot on the equipment you have.

They do sound great in stereo mode, but if you have newsgroup access, Satanika made 5.1 versions using the LFE tracks and the Prologic 2 process. I can't get on newsgroups anymore, so I don't have them myself, but I'm sure they sound excellent.

I don't have a full 5.1 setup, only 2.1 right now, so I can't completely describe the differences between the upmixing algorithms, but from what I can hear with just two speakers, Neo 6 has greater channel separation--the rear channel effects come almost entirely from the back, and the center information is removed from the left and right front channels to a greater extent. With Prologic 2 there seems to be a bit more overlap between them. Putting the speakers into the rear outputs, it seems like Neo 6 also removes the dialogue from the rears more as well. It's tough to find detailed comparisons of the two, but that's what I've been able to find out. I've heard some of Star Wars in Prologic 2 on a full 5.1 setup once, and it sounded good to me--I imagine both versions deliver good results, just a bit different. Getting the 5.1 version may be the best thing to do for surround purposes.