I have the new update (4.0) and i bought some games off of the VC and saved on my SD card but it won't let me use the SD card to play them games on other peoples Wii consoles. Anyone know why?
Your VC games are locked down to your console only. You cant put them on an SD card then expect them to play on another Wii. Otherwise, everyone would just download the game once and copy it for all their friends.
Standard 4GB SD cards are problematic, you have to pad the card with false data so only 2GB is free so the Wii can see it (the Wii was originally designed to only use standard SD cards up to 2GB). With the new update, SDHC cards of 4GB - 32GB should work fine.