Google.keystone ?? what? permissions...

Running Disk Utility, I have noticed recently the showing up of incorrect permissions related to Parental Controls in addition to the seemingly innocuous "ACL found..." messages. The Parental Control errors seem to get fixed and not show up if I repair again, but I've just seen more errors than previously lately.

The really strange thing though is some disk image showing up as open in Disk Utility. The location says it is:
/Users/mom/Library/Caches/com.google.Keystone.Framework.503/Downloads/com.google .Keystone.dmg

"mom" is a separate user that is actually named something other than mom, and I think I previously chose "mom" when older systems allowed me to specify a different short name from main name for users. The latest system doesn't appear to have that differentiation, but the old folders are still there and everything seems the same.

I have fast user switching enabled, but I am seeing this disk image open when in the main account with all other accounts, mom included, being totally logged out.
I do not have Parental Controls enabled except on one customized guest sort of account that is rarely ever used. It is not enabled on the "mom" account.

We do use Google Notifier and Google updater.

I do see this issue after "mom" has been logged in and then logs out, and maybe - though I haven't tested this - it happens when Gmail was open in her browser at the time of logging out.

I am able to eject the disk image with Disk Utility and then it goes away. I just want to know what is going on, how to control it, and whether there is any problem with the way things are functioning.

Thanks.