My Wii recently started doing this weird thing, after I use a channel for a while, then I will use the home button to well....return home but then,(and this is the problem) when I chose another channel (game,vc,ww,wiishop,mii,photo,or any other) the screen goes black and the wii locks up. the wii still makes its running sound but the only way to turn it off is to unplug it!?@? It's not a big problem, just anoying, i can usualy just reset the wii before chosing another channel and it works fine.
BUT..... WHAT IS THE PROBLEM.. and should i worry?

I noticed that my Wii started locking up (although rare) when trying to go to one of my channels...dunno if its from one of the system updates or not.

My Wii randomnly goes to a black screen and gives me a message saying "The Wii System Files are Corrupt, Please Refer to the Wii Operations Manual for Troubleshooting" (rarely, like it's happened a dozen times since 4.0) when moving between channels and the SD menu. I've called NOA Support and they are stumped, and since NONE of my files actually are corrupt, broken, or missing... It's just a minor and very rare inconvenience that NOA refuses to do anything about.

I may be linked to the last update. I've had the Mii Channel take a longer than normal amount of time to launch.

If you're not seeing any other graphical glitches I'd just write it off -- also, how long are you waiting before unplugging the machine? I'd let it sit for 5 min. before throwing in the towel and resorting to that in case it's just taking a long time. Probably worthwhile noting what Channels this is happening with too.

Weird... O_o