not so good button polyp

http://www.canreef.com/photopost/dat...2_-med.jpg?966

Please review the pic of our sick brown button polyp. We got this on boxing day and for the first couple of days it opened up nice. Since then, this pic was taken today, it hasn't opened up.

ALL water tests are good. Everything else in the tank is doing great.

any ideas or sugestions?

thanks