Sergio, that's very easy to fix. You need to change the default. At present you have it set to the classic version (possibly because you were using classic environment whilst using osx.) Simply choose an mp3, or m4a, etc. & go to File menu> Get Info (or command & I keys) & choose open with ... you'll see a list of suggested programs with iTunes classic at the top. Choose iTunes OSX version instead, if you don't see it on the list then go down the bottom & choose the browse option to find it & select it. Then choose the option to always use it to open that type of file. BTW I had something similar happen to me. It was a while back so I can't remember which program it was ... possibly iTunes. But anyway, doing it that way, you can control the exact program & version that opens the file by default. There's at least a 4 or more programs I prefer the previous version to be the default. Speaking generally that is, not necessarily LW related.

Actually I suffer the same problem with my screen going blank when I turn the brightness control up to full. hehehehe lol

But yes, Jaguar now seems to have an issue with some skins. Pinstripe I think it is I can't remember.