Clean the disk with water.  I had the disc errors for games, and they weren't scratched.  Just use a wet paper towel...

Hmmm. I've never had a Disk Read Error on my Wii. I've had it since launch. Froze twice in that time, but nothing else

...I did a test again. I putted it vertical and got a disc error... Turned off, just changed to horizontal and it worked.

O_o So I'll get it replaced... >_> Arg so troublesome...

This is the first time I get an issue with a console.

I had your problem about 4 times, but that was ages ago.... thrice with the shop channel and once with the trial version of the internet.

in terms of game problems only SSX Blur has ever crashed, it seems to do it sometimes if I am on it for a long time.... so far only three times.

I have never had a disc read error though like I had with the GC, which wouldn't read the disc in the first place... or brought up the message in game... I think about 20 times I had the "an error has occurred, turn off and read the intruction manual" comment in the whole GC life, which is pretty good i suppose. (except once on WindWaker i had not saved for about 2 hours when the error message came up... grrr)

I never had this kind of message with the Gamecube... Really! Now I understand how people feel when they get issues with consoles... Heartbroken... Feel all alone and cold... XD

No seriously, can someone explain to me how come it ALWAYS works when it's horizontal but fails when it's vertical? O_o

 Yeah, it's a hardware problem, it happened to mine.  My system would click repeatedly while reading discs and sometimes it'd just zonk out and say "Disc Read Error."  It's a system problem. 

Just call up Nintendo and get a replacement...that's the best thing you can do.  Nintendo's systems are great quality overall, and the few with problems will get replaced easily.

It would do it to me when horizontal as well, though not as often I bet.

Surprising that this many people have had Wii hardware problems. But the big warranty and easy service certainly made up for it.

lolita, if it happens all the time when vertical definitely get it replaced. I was thinking it was just a one time random thing.

As for the freezing when resetting thing, I was thinking about it and it seems to happen the most when playing Fire Emblem. I can't really say if any other games have failed to load properly.

I had those problems a good bit when I first got my Wii. It occasionally does it here and there. Most of the time it does that horrid clicking sound, like some tiny plastic hammers are beating my disc to death. But it must be something else since none of my games are even nicked. I've had the occasional disc read error, but that's pretty rare. As far as games locking up, I've had a single instance of this happening with Zelda and Fire Emblem(when resetting), but multiple times with rush-jobs like Madden 08 and Red Steel(but that's not what you're talking about).

If it's happening that often, it must be a hardware problem. Get it replaced while it's under warranty. I wish I had done mine when I had the chance, but I'm just paranoid about that kind of thing. My Wii works fine 99% of the time, though I still get the occasional scare.

If it's working horizontal, and not vertical, it could be a problem like people were having with the PS2. I believe with the PS2 it often had to do with a cheap plastic wheel that was used to spin the discs. From what I read it would warp over time with use and gravity, which is why some people's worked better after switching it to horizontal from vertical.