schemaToInputEx - Different results in Firefox

[mattattttt]

I'm using schemaToInputEx successfully. However for one of my forms,
which defines a group of fields, returns the fields in reverse order
in IE and Chrome but displays them the way I would expect in Firefox.
Here is a snippet of the code:

var builder = new inputEx.JsonSchema.Builder({'schemaIdentifierMap':
schema});
var inputExDefinition = builder.schemaToInputEx(schema["ASchema"]);
inputExDefinition.parentEl = 'someDiv';
var myForm = new inputEx.Form(inputExDefinition);

What is happening is the inputExDefinition.fields are in reverse from
IE/Chrome to Firefox. My thoughts are this this is down to the way the
browser processes for ( var a in b ) statements.

Can anyone think of a way around this? without putting if (IE/
Chrome) inputExDefinition.fields.reverse();

Thanks in advance