I've had problems with recordings losing sync also. At first I thought it was Xmame that had the problem. Then I descovered that Xmame uses autoframeskip as default, I used the command line -noautoframeskip and the games I had problems losing sync would now playback properly in Xmame. Frontline was one of them.(posted 9600 days ago)I played BBH's recordings on another game and it lost sync after the 1st level, I then tried JSW's second place recording and it lost sync at about the same point. I played back my recording and it played back fine.
I tried playing back my frontline recording at work with w32.V35 on my NT machine at work and it actual plays the game upside down and does not play back properly. I then played BBH's recording that failed in Xmame on my NT machine at work and it also lost sync after level 1.
It looks like some games are not cross compatible for different platforms amnd/or versions.
PS: Can someone with a dos version test my frontlin recording?