You shouldn't ever pull the battery out of the wii without first disabling the wiiconnect24. There's a bug in the firmware. I"m sure it will be fixed eventually. That is what generally causes this problem.
I had the same issue when I modded my wii, I forgot to turn off the wii connect24 before I removed the battery. Anywho, here's the directions on how to fix it:
1. Turn on Wii.
2. Back up your game saves to SD card, and your mii's to your wiimotes.
3. Turn off Wiiconnect24 in your settings.
4. Turn off Wii. Unplug Wii.
5. Take out battery in back of system.
6. Plug in Wii and turn on system.
7. Make sure Wiiconnect24 is still off and format Wii memory.
8. With battery still out, turn system back on and setup all your settings.
9. Turn on Wiiconnect24 and check to make sure your news channel and forecast channel will again update and run as normal. Don't forget you will have to set up your internet connection and time and date settings again.
10. Turn off Wii. DO NOT UNPLUG.
11. Reinstall battery.
12. That should get the updating back to normal.
13. If upon first insert of a disc, you get a read error. Unplug and plug back in the system. Everything should then be fine.
It's a pain in the butt, but it worked for me. See if this doesn't get your fixed up.