I am having a strange issue. Occasionally when installing new packages, I will get a system crash notification which I will report. The environment then becomes unstable, unity crashes and all open windows, loose title bars, and the main launcher shuts down. I usually have to run the command unity --replace to restore functionality, but ultimately end up having to reboot. Upon booting back up I find all of my user-installed packages are gone and I have to reinstall them via apt.

Please tell me someone else is having this issue, because this is the second system and third install I have had this issue on.