It may or may not have been Nintendo’s intent, but a newer optical drive in some Wii consoles seems to be blocking mod chip functionality.
Techtree says that the new drive makes mod chips useless. They report that the new optical drive revision was found in the Australian Wii model (LAH1098xxxxxx) of the console, but hasn’t been reported anywhere else. This post at Wiinewz details the technical changes. It seems that a controller chip has been removed.
Who are we kidding? Nintendo knows about piracy. And this change sounds deliberate. I’d guess that Nintendo will eventually put these new optical drives in all shipping Wiis. Unfortunately for Nintendo, there are already plenty of “old” Wii consoles out there.