Don't update from Nintendo
As you know, updating from Nintendo will kill the region free ability of your modchip. This is no good, so don't update above 4.1 and you won't have this issue. Who knows what future updates will do, so stay away from them.
You will need to block updates using your chip, or even better- priiloader, which will also block online updates.
You will also need to update an ios file from time to time. If you do need a new ios to play a game, this is how to update without help from Nintendo.
If your not on 4.1 yet, a disk update to 4.1 is a good idea- it will install most need ios for you for the foreseeable future. Don't update online.
Backup and format your sd-card
Extract Dop-Mii_v12_CB2_BB2.zip to sd:\
Click the SD ICON from the channel menu
Load the boot.dol, dop-mii starts
Select Install ios36 with fakesign
Install from NUS if the wii is online
Install from SD for offline install, and extract these wads to sd:\wad
Be sure to apply all 3 patches to ios36
This only needs to be done once.
Select ios36, press A
Select ios, mios, bc, press A
Install the required ios file, without patches is fine.
Review this thread for required game ios versions.
Only update the ios if you need to. IOS 30, 50, 60, 70 are system ios- don't muck them up.
Ok so you have your ios updated. I also recommend priiloader to block updates. If you don't have it, review below.
Extract Priiloader_0.4_BB2.zip to sd:\
and Extract hacks.ini.zip to sd:\
Click on the SD ICON again, priiloader installer will run. Install priiloader.
Hold reset and boot the wii while holding reset- priiloader will load
Click hacks, enable- "block disk updates", and "block online updates"
Now your wii is safe from those evil updates. From now on you will update manually via dop-mii if ever needed(rare).