Ok, so I'm using a Sound blaster CT1740 with a Yamaha DB50XG Daughterboard.

This setup works great with games like Doom 1+2, Heretic and Hexen but when it comes to playing Duke3D or Blood, the games and music lags for 3-5 seconds at a time every 30 seconds or so making them unplayable. This is only when selecting general midi for music playback. If I change the music settings to use the sound blaster instead, the games run beautifully.

Very strange because, as written above, all my other games use general midi without issues at all. No hanging note bug etc

DSP is version 4.05 if that helps.