GermGuardian H3010 Humidifier - I received this as a gift December 2011 and used it until spring 2012 where i emptied and stored it for the summer. I pulled it out last night, plugged it in, filled with water and the refill light continues to flash and the unit will not produce vapor. I've done a bit of online searching for suggestions and have found this is a common problem. Any solutions/suggestions?