Hi. I'm the same guy who posted in http://ubuntuforums.org/showthread.php?p=10113145 . I'm still having problems with x11vnc and I'm starting to think that it's a bug in x11vnc (or at least, an unfortunate interaction with the X11 X Windows server). I found out that x11vnc will also crash when I click the right mouse button, but, oddly, it only crashes after I've click it several times (it seems to be random how many times are necessary for a crash). I can send you my entire x11vnc output in an email if you'd like. I've tried remapping button 2 and button 3 (e.g., :Button2: and :Button3, but it doesn't improve the situation. If it matters, I'm running xorg 1:7.4+3ubuntu10 . Perhaps there's a bug on that side (e.g., a poor XTEST implementation)? Thanks.