Are you adding any calcium into your system? If you are you could reduce what you are adding or stop it completely until your numbers come down. If you are really worried about it you could do some water changes, but I'd be inclined to just let it drop on it's own.
Did you just get a new test kit or anything? Sometimes the different kits (Salifert, Red Sea, API, Hanna, Etc.) produce different results. A new kit could produce different results for you.
I found this very helpful: [video]http://www.advancedaquarist.com/2002/11/chemistry[/video]