Rickster is on the right path. Any liquid compound always has a certain amount of chemical reactions going on and some molecules will get released as gas. Carbon Dioxide in drinks was just an example to demonstrate the point.
The fact that the batch I vaped on Sunday became better once I vaped a certain amount demostrates that whatever it was disappeared. My guess is the heat from the coil helped speed up the process of releasing whatever chemical was causing the off taste and it evaporated away. Even a basic knowledge of chemistry tells us the as you heat up any liquid the chemical reactions speed up.
It therefore isn't too much of a leap to think that giving these gases enough chance to be released out of solution and excape may be the right thing to improve the final result.