I have a Tripp Lite AVBar10 that shows two green LED on the outside ("protected" and "line OK") and a red LED in the middle ("ground").
I went to Lowes and got an outlet tester, and all the circuits checked out okay. When testing the AVBAR10, it reads okay in all circuits on the strip. I spoke with Tripp Lite and they sent me a replacement, but it reads the same.