Wow, thank you guys VERY much for clearing this up for me! No wonder my colors have been getting darker and taste has changed since I started leaving it in the primary for longer. I have never seen nor heard of a bucket with an airlock on it until today.
Mine and everyone I know who homebrews use a 10 gallon primary with a more loose fitting lid that would be redundant to put an air lock on.
I think thats the same as mine, where there is plenty of breathing room where the lid touches the bucket. Totally different concept to a closed fermentor sitting for a month.
EDIT: I'm starting to freak out now - its too late to carboy tonight but I have two of my most complex beers that have been sitting in the primary for 8 days now....