Apparently there is a double bug [in version 4.35 on Windows 7 x64]
1] When converting a file that has "ø" sign in it, it some cases that sing will be changed to ordinary "o". For example when converting from M4A to WAV and from MP3 to M4A, but not when converting from WAV to MP3
2] When converting a file that has "ø" sign in it, it some cases that file will be speed up by [i think] 200%. For example when converting from M4A to WAV, but not when converting from FLAC or MP3 to WAV