CFGrid and checkboxes

I have included the code.  My problem is that I am always getting the error exception thrown and not caught despite adding cftry/cfcatch blocks.  If I don't set selectmode="edit" and include OnChange my grid displays except I get the word false displayed instead of a checkbox.

<cfgrid format="html"  name="grid_Tables" pagesize="10" autowidth="true" striperows="yes" width = "99%" selectmode="edit" bind="CFC:qry_GetUser.getAllUsers({cfgridpage},{cfgridpagesize},{cfgridsortcolumn},{cfgridsortdirection})"onchange="cfc:qry_GetUser.editData({cfgridaction},{cfgridrow},{cfgridchanged})">
   <cfgridcolumn name="UserID" display="No"/>
   <cfgridcolumn name="opt" header="" type="boolean" width="46"/>
   <cfgridcolumn name="Name" header="Name" width="150" type="string_nocase" select="no" />
   <cfgridcolumn name="Email" header="EMail" width="150" type="string_nocase" select="no" />
   <cfgridcolumn name="RegistrationDate" header="Registration Date" width="150" type="string_nocase" select="no" />
</cfgrid>

<cffunction name="editData" access="remote">
                <cfargument name="gridaction" required="yes">
                <cfargument name="gridrow" required="yes" type="Struct">
                <cfargument name="gridchanged" required="yes" type="Struct">
                 
        </cffunction>

The problem is that in edit mode I get an error thrown so the grid
doesn't display at all.  I am wondering if I have a problem with:

onchange="cfc:qry_GetUser.editData({cfgridaction},{cfgridrow},{cfgridchanged})