I tried it with both and only one pdf mime type. It didn't seem to make a difference for me. What does the "x-" indicate, as there are several mime types that use it?

Don't know why I'd decided on inline, (thought I read a definition), but "attachment" makes more sense. Again though, it didn't make any difference for my setup.

Also, if this can't really be accomplished, how does Download.com do it without fail? Do they just assume no one is stupid enough to set their browsers to run executables?

Thanks for everyone's help.