Does Alice "shut off" or does your computer? If Alice shuts off what do you have to do to start using Alice again, reboot your computer? If Alice "shuts off" can you use your computer for anything else, i.e. M$ Word or something without having to reboot?
The only time I have ever seen Alice lock up is when a teacher activates a tool such as SychronEyes on student machines. That's not to say Alice will not lock up on older, slower machines.