Yeah, read the other post about a 'stuck' fermentation. They lost a gallon of mead due to the volcano of CO2 rushing out of solution.
There's always CO2 in solution unless you degas or let it bulk age a really long time. A wine degassing wand is a good investment if you continue meadmaking (or winemaking)
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10