If I'm reading correctly, everything worked fine using your monitor instead of his. Someone else posted a problem solution the other day where the system was responsive (crash vs. running fine) to the specific refresh rate applied to video. If the system is connecting to a plug 'n play monitor it will automatically adjust the refresh rate to each monitor it is connected to. So, try forcing a specific refresh rate, change video modes, or try disabling on board video and installing a new adapter...