[K12OSN] How to diagnose terminal which keeps logging user off?

[joseph.bishay at utoronto.ca]

Hello,

I have a terminal which acts all nice and pretty until someone starts
using it. After a few minutes (undefined) of Internet browsing or word
processing the user, without any warning, will find that the terminal will
have logged them out and in front of them they will see the k12ltsp login
screen (it is as if someone hit ctrl-alt-bksp without them noticing!).
Obviously this is an issue, but I don't know how to diagnosis it. Can
anyone give me any questions or direction to how I can approach this?

Thank you kindly,
Joseph