Photos would help - black spots could be a lot of things.
1. Are they tiny little black spots everywhere like pin pricks, or are the traps turning black/brown in larger patches (which is normal for plants going dormant)? This is the most important question.
2. Are the plants all outside or indoors? Did you move them recently?
Take a look very closely at the plants and see if you can spot any tiny moving critters. A strong magnifying glass or photos with a camera in macro mode might help.
Read this thread, especially the last post - it may help: http://www.flytrapcare.com/phpBB3/viewt ... f=3&t=3026
If it does turn out to be something like spider mites, other pest, or fungus for that matter - NEEM IT: http://www.amazon.com/Green-Light-Organ ... 000GXQMQC/
You can get Neem Oil from Wal-Mart. Lowe's, Home Depot, and plant nurseries likely also carry it. If all else fails, just order it from Amazon.
I know the Green Light brand is good because other CP growers have used the stuff successfully.