Alright I've tagged a test file using the program mp3tag v2.41 as the flac site recommended with APE, ID3v1, ID3v2.3 ISO, ID3v2.3 UTF 16, and ID3v2.4 UTF 8 tags. And Hurrah!!! It read every one of them. Now it didn't diplay album art for any of them. But it's getting late, I'll play more tomorrow. Here's the link if you want to check the program out.
http://www.mp3tag.de/en/