I went to Nintendo's customer service
and looked for information on the matter. It appears that certain games have disc reading issues, and Metroid Prime Trilogy was on that list.
Nintendo Customer Service wrote:
Support for Metroid Prime Trilogy - "No disc found" message, single disc
A repair is recommended:
Based on the information you have provided, it appears your Wii console needs to be repaired.
"Why is this repair necessary?"
Metroid Prime Trilogy utilizes a double-layer disc which has a large memory capacity. A very small percentage of Wii consoles may have trouble consistently reading data off this large capacity disc if there is some contamination on the lens of the disc drive. Nintendo has specialized cleaning equipment that can resolve this problem.
"How can I get this fixed and how long will it take?"
For the United States and Canada, Nintendo is upgrading inbound and outbound shipping to expedite the total repair process. Specific repair times will be provided as you fill out the repair form. There is no cost for the repair or shipping. Please note: returning the game to the retail store will not solve the problem. So we encourage users who are experiencing issues with playing this particular game to utilize this repair order process.
"What if I have Virtual Console games or other stored data on my Wii console?"
Due to the nature of this particular issue, you should not lose any of your stored data. In some rare cases you may have to re-download your Virtual Console games from the Wii Shop Channel, but there is no cost to doing so.
This is the page the info is from: http://www.nintendo.com/consumer/repair ... meCode=MPT
I highly recommend you follow their advice and fill out a repair form to get your Wii fixed. Hope I helped.