I want to apologize in advance for the spelling mistakes I make in this post. The wounds from the hot pokers are still fresh in my eye sockets! I've been struggling mightily with the Remote Wonder Plus install on a fresh copy of MCE. I completely understand the frustration put forth in this thread. I get the same errors about DLLs not being registered and this happens to me after a fresh install of MCE. How, in 2006, can the installer be this hosed? It's unforgiveable, really.
Fortunately, I believe I've found a fix that requires no registry editing, no DLL copying (and re-registering) and no hot pokers in your eyes.
I believe ATI has somehow screwed up the English only version of the 3.03 Remote Wonder installer. I had problems (off a fresh install of MCE) with the file 3-03_rw_enu.exe. This version gave me the errors everyone has been getting. But, when I downloaded and installed the multilanguage version 3-03_rw.exe the installer worked as expected. No errors upon reboot. I was left with a fully functional Remote Wonder Plus after plugging in the USB receiver.
I even tested this by wiping my drive and doing another reinstall of MCE. It worked perfectly. If someone else could confirm I'm sure we'd all appreciate it.