Problems with multiple child accounts

Hi,

I've got 3 kids and installed the free version of Norton Family to test it before upgrading.  Its installed on one computer (Windows 7) which my 3 kids use (Standard Users).  The program first appeared to work fine, but now we are noticing that it is "scrambling" the kids.  So if "Jennifer" is on the computer, I will get notifications saying that "Oliver" is trying to connect to a blocked web site.  And when "Charlotte" connects for the first time in a day, she will get a warning that she's used up all her time for the day, when in fact it was her brother who was using the computer before her.  I've already checked, and the kids are definitely not signing in to each others' accounts.  Whats going on?

Another question:  whenever a kid uses the computer I get a message that : "Norton Family's web browser monitoring component is either disconnected or disabled. Please restart the web browser or restart your computer. "  Every time.  Why is that and what can I do to fix?

Thanks very much for your advice!