Sierra game freezes on game restore operation

Trying to play Ecoquest CD DOS version here with the MT32 OGG soundtracks, but the game freezes when I try to restore a save.

I downloaded Pix's v1.3SVN, and the Ecoquest OGG files. Unpacked them all into the game directory.
Everything runs like a charm and the soundtrack works perfect until I try to restore a save game after shutting down scummvm.
In other words, if I try to load a save game I just made in the same session everything works perfect. If I shut down and restart scummvm everything works until trying to load (restore) one of my savegames.

I've tried this on 3 different computers, 2 with Windows XP and one with Windows 7 starter edition. Actually, on one of the windows XP PCs it did restore the savegames on occasion after shutting down the program so this seems to be a very nebulous problem (sigh).

I'm also pretty sure it's related to the OGG soundtrack since when I choose the Ecoquest Windows version (comes on the same disk, but apparently doesn't support the OGG sound files since I don't get any music), all the computers load the savegames perfectly.

Any ideas?

I've not got the CD version of Ecoquest but it was fine with the floppy version last time I tried it. There could be something wrong with the last build I did as I don't think I've actually tried playing a Sierra game on it. I've not changed anything in a while but things can break as the scummVM team update the code. I'll have a look at it when I get the chance and get a new build up in the next day or two.