i had my wii modded with cios249 rev17. never ever had any issues.. until i got defjam rapstar and it wouldn't work. so with some research, i did a few tweaks (hermes), and had to get to cIOS 249 rev 18 for it to finally recognize the mic. every game works fine except 1 aspect of Smash Bros Brawl (usb loader gx) that i use somewhat often. although a minor issue, still a nuisance. having rev18 causes a conflict in SSBBs feature to send replay data to friends, often times it will say i am not connected to the internet. usually a boot of the wii will do the trick, i will be able to send just 1 replay. then it gives the error again. it works just fine with the retail disc that i have.. it's a minor issue, i am not really looking for a solution, but it's an issue nonetheless so i figure i'd post it
You can use a different cIOS for SSBB. Try Hermes 222.
Wii System Menu X(4.1u)-CFG USBLoader 7.0, D2X cIOS Pack