As I understand it, you are talking about the original Sierra version of QFG1VGA, right? The game is made in Sierra's SCIV interpreter, which has no technical relation whatsoever to AGS (although they can produce similar looking games).
This sounds like a timing issue due to the speed of modern equipment, so I recommend that you try a CPU slowdown program like CPUKiller
Check these products:
http://www.cpukiller.com/products/cpukiller/index.html
http://www.the-underdogs.org/tools/turbo.zip
You might also want to read the guide to running old games on new equipment (XP in particular) at Home of the Underdogs: http://www.the-underdogs.org/guidewin.php and http://www.the-underdogs.org/guidedos.php#f
Edit: This specific speed issue in QFG1 is discussed at http://www.sierraplanet.com/~ugarte/Resources/Technical.htm#SpeedQfG1
This sounds like a timing issue due to the speed of modern equipment, so I recommend that you try a CPU slowdown program like CPUKiller
Check these products:
http://www.cpukiller.com/products/cpukiller/index.html
http://www.the-underdogs.org/tools/turbo.zip
You might also want to read the guide to running old games on new equipment (XP in particular) at Home of the Underdogs: http://www.the-underdogs.org/guidewin.php and http://www.the-underdogs.org/guidedos.php#f
Edit: This specific speed issue in QFG1 is discussed at http://www.sierraplanet.com/~ugarte/Resources/Technical.htm#SpeedQfG1