Same deal. Fully installed X2 Producer then re-ran the Symphonic Strings installer. Same results. :-/
edit 7:45PM CDT: I'm done being an idiot. Reinstalled DimPro and then tried the strings again, and voila all is well. Sorta. It stuck them in a Multisamples folder on teh root of C:. I moved them to the rest of the Dim Pro samples and can use them.