[plt-scheme] mysterx problem

After resisting for as long as I could I am now forced to write some
code for Windows. I know, I know, but they made me. Anyway, I need to
deal with COM objects so right away I go download MysterX and install it
on a Win2K box. No build, just from the install. Unfortunately when I
(require (lib ("mysterx.ss" "mysterx")) I get back the error: 

"mxmain.ss: you seem to be missing mxmain.dll; you need to build MysterX
in plt\\src\\mysterx\\"

Looks like the DLL isn't getting found/loaded. I manually registered
(reg32, whatever that is) the 2 DLLs mentioned in the mysterx doc but
still no go. What incantation am I missing?