Sometimes custom field disapears

[kubasienki]

We cannot find any regularities in such behavior. Simply from time to time my custom field disappears from form. here's code:
`function() {
Formbuilder.registerField('thumb', {
order: 15,
view: "<% for (i in (rf.get(Formbuilder.options.mappings.OPTIONS) || [])) { %>\n <div style="font:normal normal normal 14px/1 FontAwesome;">\n <% if (i==0){ %> \n <div class="fb-thumb-up a_<%= i %>">\n <% } else { %>\n <div class="fb-thumb-down a_<%= i %>">\n <% } %>\n <input type='radio' <%= rf.get(Formbuilder.options.mappings.OPTIONS)[i].checked && 'checked' %> onclick="javascript: return false;" style="display:none;"/>\n \n <%= rf.get(Formbuilder.options.mappings.OPTIONS)[i].label %>\n \n \n \n <% } %>",
edit: "<%= Formbuilder.templates'edit/size' %>\n<%= Formbuilder.templates['edit/countable']({ includeOther: false }) %>\n <%= Formbuilder.templates['edit/thumboptions']({ includeOther: false }) %>",
addButton: "<span class="symbol"><span class="fa fa-circle-o"> Thumb",
defaultAttributes: function(attrs) {
attrs.field_options.options = [
{
label: "",
checked: false
}, {
label: "",
checked: false
}
];
attrs.field_options.size = 'S';
return attrs;
}
});

}).call(this);`