As it says on the web page, it hasn't been worked on in a while (pre-vista) so it could possibly be incompatible with Win7. Is there a chance that you're running the 64-bit edition of Win7? That might be it, too. I'll bet that DLL only works in 32-bit Windows.

I wonder if it would work if you ran a 32-bit XP session in a VM. Or even, tried running Jemplode or the JRE in XP compatibility mode (not sure how to pull that off exactly).