News/release from Vader347: of the Media Player for Wii.
Vader347's version of mplayerwii with the widescreen bug fixed can be found here. Vader347 claims that the only real change is one line of code (as recommended by pepsiman):
"rmode->viWidth = 678; rmode->viXOrigin = (VI_MAX_WIDTH_PAL - 678)/2;" after "rmode = VIDEO_GetPreferredMode(NULL);"
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