It has been reported that when a machine that is NOT running RAM Doubler attempts to mount a machine that is file sharing, AND running RAM Doubler that both machines can lock up.
The crash is severe enough that force quiting, and Programmer's Switches are of no use.
The resolution for this problem is to install Network Software Installer 1.4.4 on both machines. Connectix is aware of the problem, and this is their recommendation.