There has been several threads started on just this problem so it would appear that this problem isn't isolated.
Before removing and reinstalling the gear as PatR suggests (which is a sound solution by the way), first try to get the gear moving by doing this: remove the props and camera and with the aircraft switched on but with the motors not armed turn it upside down (so that the gear is in the air above the aircraft) and toggle the gear switch several times to try to get the gear to operate normally. Sometimes this procedure works and sometimes it doesn't. If it does work your problem is resolved. If not, then go to plan B as PatR suggests...removing and reinstalling the gear isn't a hard job by any means (even a nutter like me can do it) but if you can resolve the issue by turning the aircraft over to cycle the gear then you don't need to remove the gear at all.
If you can't resolve the problem by either of these two methods then come back to us so we can advise further.