MIDI access (not only adlib) hangs WinNT on QEMU 1.7.x

Windows NT 4.0 and 2000 (including the latest git release), when enabling adlib (with sb16 already enabled) or the built-in synth of the es1370, hang on QEMU 1.7.x (also with 1.7.50) when they try to play MIDI files (like canyon.mid, etc). I have already tried bisecting but seems that this bug has been introduced sometime in 1.7.0's development time.