If you want an update, only use your pal discs or use the internet, If you use an NTSC disc to update you may very well end up with a semi brick!!!!! Since your on 3.1 you can do a couple of things.
1. Get the homebrew iso loader, burn that to disc and install homebrew, Then use wii update patcher on one of your game isos to put firmware 3.2 on it.
2. Use the homebrew iso loader first and install homebrew, Then use the internet to upgrade, It will put you on 3.4 firmware, then use the downgrade guide to go back to 3.2
3.2 firmware is the best to use with homebrew etc, There are some links in my signature, Ones about 3.3-3.4 firmware info, so you should read that, Also I have a very good downgrade tutrorial as well.
lastly dont forget to look at this
plenty of info there too....