Thanks Overlord.

I think the problem lies in way the zlib library I'm using is working. Sometimes, it leaves 4 bytes, sometimes it doesn't. The uncompressed data *appears* to be intact, though I haven't tried using all of it yet.

I'm going to continue looking for a C# zlib that actually works. In the mean time, I just close my eyes and ignore the extra bytes. Hopefully things will work out.

-Nag