I asume you are using lmms 0.4.13?
well
- default is 160 kBit/sek, but doubt thats the issue, but try...
have you tried all interpolation settings?
Is the exported file empty or does the export stop during the process?
Latest version, I tried all tweens .. the file size but has no sound, no arrests during the process (too fast)
Same problem on XP SP3
Setup: SDL audio interface, setting correct audio drive: (