This is so weird. It should have worked. The problem doesn't seem to be the location were images are. Can you please attach here "sysimagefolders.ini" and "EmuCon.ini" files so I can have a look ? It's in EmuCon's root folder (same as EmuCon.exe).
What format are the images ? JPG ? What image layout are you using in EmuCon ? What EmuCon version are you using ?