Mike - Hah!
Do a happy dance! Hee hee hee. I've found in the past that this situation always has one reason:
The one grumbling about other people at the meetings, people who often do things right, is the person trying to take the attention off his own bad deeds off of himself and direct it at another person.
In our organization they usually don't last too long because they can't keep the attention off of themselves forever.
Sounds like you're doing good. Chin up. He can't cover up his own insecurities by shedding light on what he believes are flaws in you. Your good deeds will outshine his bad.
God bless you - keep smiling!