Grim Fandango: Long lost bug found, fixed!12 Jan, 2012, 20:39 | Posted by: ThunderPeel2001 | Source: ResidualVM.org
A bug so buried that apparently not even Tim Schafer was aware of its existence:
The bug is now fixed for players using the latest version of ResidualVM to play Grim Fandango.
"I had no idea that there was a bug in Grim that caused a critical dialog not to play! :O! But these guys fixed it."
You can get ResidualVM for free here: http://www.residualvm.org