Thanks for your patience Blair and the updates on this issue you have been researching.
In order to resolve this issue, because this is more of an Mac OS X kernel panic problem, the only way to resolve this, problem with the frequency of the crashing of the WindowsServer is to refer to this guide that Apple recommends for resolving higher than normal kernel panic issues like the ones you are experiencing on your iMac.
Here is the link: Mac OS X: About kernel panics
I am providing you this guide Blair, because it is a great resource to refer to to help resolve these kernel panics on your iMac.
Finally, from my experience in troubleshooting Macs that experience frequent kernel panics, the quickest way to remove this problem is to run a full Disk Repair procedure using the Disk Utility application by booting up from to it, with your Mac OS X 10.6 Installation disc.
If the Disk Repair does not resolve the kernel panics, the only other viable options would be to take your iMac in to a local Apple Retail Store for further diagnosis and repair.
Of course the latter is a last ditch option if nothing else works, but I must advise you to keep this as still a possibility, because kernel panics, or temporary fatal errors are not always software related, they can be hardware related. If the panics are hardware related, that is more serious and will require professional tech support to root out the problem before it becomes worse.
I see you are offline at the moment, but I hope this answer does reach you. Please feel free to respond with any additional questions. Seeing that you are still working to tackle this issue, I will be watching for your updates in order to assist as well as I can based on stated cirumstances.
Thank you again for coming back online to JustAnswer.com. I will watch for your next update as necessary.