When working with P6-Client best practices include logging out of P6 explicitly when you are going to be idle for awhile. For example if you are going to go for a meeting.

The reason for this is it does not always let go of your session cleanly so you get strange errors or data is not saved.

Another thing we have noticed is if you work on a laptop and move from your office to a meeting room a lot that again you really want to logout out of P6 and also likely shutdown your computer.

This helps to make sure your startup is clean and no caching problems.