Hi,
I initially had problems getting my CF adaptor with an 8GB SD card to boot but found using EOSCard that by just pressing the "Save" button then selecting the latest build and allowing it to be downloaded and installed onto the card, deleting all the files from it after it had finished and copying the 400PLUS BIN file to the root of the card my camera booted into 400PLUS and everything worked fine. I don't know if your card being WiFi would make any difference but it's worth a shot.
Good Luck
Dave