jquery format currency plugin problem! Not working without symbol!

Question

I have verry strange problem.

I've found this plugin http://code.google.com/p/jquery-formatcurrency/ which in it's basis do the job, but I need a little customization. I want to use it's features but when I set settings like this

$.formatCurrency.regions[''] = {
        symbol: '',
        positiveFormat: '%n',
        negativeFormat: '-%n',
        decimalSymbol: ',',
        digitGroupSymbol: '.',
        groupDigits: true
    };

where I don't wat symbol in my formating, after hitting 4 digits result is

123.4

but after hitting fifth digit it's

123,45

somohow . converts to , and then it's not the same number anymore. I was looking to source but I'm not realy jquery type :) and can't rely find the bug. If I put theese settings

 $.formatCurrency.regions[''] = {
            symbol: '$',
            positiveFormat: '%s%n',
            negativeFormat: '-%s%n',
            decimalSymbol: ',',
            digitGroupSymbol: '.',
            groupDigits: true
        };

everything works just fine. Problem starts when there is no symbol, and decimal and digitGroupSymbol are set like in first example.

Any ideas please.

I looked at numbers of plugins and this is the one that satisfies my needs when it works, but it doesn't work in my case.

JQuery gurus please help :)