In my blog entry Crashing Visual Studio 2005 for Fun I described how to crash Visual Studio 2005. Scott Guthrie followed up, and since then I was in permanent contact with team members. After some research, it turned out that it (a) was seemingly reproducible only on my machine, and (b) likely a tooltip issue.

What is going? Well, my machine is equipped with a Matrox P750 and has three monitors attached, spanning a single 3840x1024 "display". This strechted single display is managed by Matrox PowerDesk-HF, and it comes with a couple of desktop settings to make applications play nice on three physical monitors. One of those options is "Prevent tooltip spanning in strechted mode":

What does this option do? Imagine that I have an application full screen on the middle monitor - without that option turned on, tooltips "overflow" to the monitor to the right (you only see the background image in this screenshot, but that is the 3rd monitor):

Now guess what - once I turn that option on, VS05 crashes the way I described in my previous blog entry. It took me a couple of reboots, configuration from scratch and quite some testing to finally figure out the root cause for this crash.