I'm used to 1 = true, 0 = false, but still, I tried a sample form set up like this and it worked as anticipated in the browser (InfoPath & SharePoint 2010). If I were troubleshooting this, I would probably put a text box on the form bound to the field to see what the actual value is. I'd check the default value for the field. I might try changing cleared to 0 & checked to 1. What version of IP / ShP?