I was thinking about something like SmartDrv, but it seems you're only using DOS buffers with no read-ahead, so doesn't seem like a factor.

Anything that simplifies the environment might help; and as I mentioned before, trying different versions of CuteMouse. However, it's not clear how the patch program is involved because it's just monitoring file reads that occur many times before the point in the intro you describe.

Feel free to fiddle with different things if you'd like, but under the circumstances it may be better to just live with the possibility of a song that doesn't play quite right every so often.