I've also found .apk files that give "error while parsing" responses, while downloading from other sites produces an installable file.

I also spent several hours today I'll never get back installing the stupid "emulator", only to find out that "Market" doesn't download the .apk files when it installs even FREE apps, so there is no benefit in trying to get at Market apps that way. Oddly enough there is a whole thread on people doing it, but no one has actually reported success AND detailed how they did it! (more frustration)