My fitbit is playing up

I have been using it for a few weeks now and increasing activity. I have been getting to 10k steps for the last few days. My wristband and the activities thingy show the same readings. The dashboard shows different, lower reading, which is so annoying. The web site is hopeless - when I tried to get info there I ended up with a request to start a twitter account.

Any words of wisdom on this apart from ignore the lower reading...