Nothing much has changed IMHO. I'm running Housebot on server 2008R2 64 bit and it was very stable for years. I don't get HB crash dumps for some reason. HB runs in a script loop that reruns it after cleaning/compressing the database.
Without a dump file, you will need to start eliminating things one at a time. I'd start with any scripts that you are running or if you are using the email checker device. Disable them and see if the problem goes away.
Also, if you've installed anything new on the system, it might have re-installed some shared libraries that could point to the problem.