I just finished a home wiring project which has a set of outlets protected by a GFCI outlet. I was testing them with an outlet tester and noticed something odd:
Immediately after a GFCI test, my outlet tester reported that the GFCI protected outlets had an open ground. If I did a second test, the error went away.
I was able to repeat this consistently - every other test I'd see an "open ground" indicator.
Is my GFCI outlet defective?
Update: I'm using a simple outlet tester, like this one.