On my 3.4.1 implementation with the new theme customizer and the latest version of Grunion Contact Form....
Grunion appears to get validated with errors immediately when the theme is loaded up via the customizer.
As the user is logged in at the time, Grunion auto fills the user names (as it is supposed to do, but gives validation errors (name . email must be entered) on initialisation, yet teh validation errors appear, I am guessing that the validation (submit?) must be being triggered before the fields are validated.
Obviously that doesn't look too neat.
I will investigate further, but if any one has found a solution, I would be most grateful if you could share.