Please supply code to reproduce.

Ignoring the encoding issue, the following code:

$minprice = new Zend_Form_Element_Select('minprice');
$prices = array(0 => '20000');
foreach ($prices as $price) {
    $minprice->addMultiOption($price,'£'.number_format($price));
}
$minprice->setView(new Zend_View());
echo $minprice->render();

...produces:

 

£20,000

Form extends Zend_Form in the usual manner (as per the quickstart)

In the init() method:

$minprice = $this->createElement('select','MinPrice');
        $minprice->setLabel('Minimum Price')
                 ->addMultiOption('0','No Preference');
        $maxprice = $this->createElement('select','MaxPrice');
        $maxprice->setLabel('Maximum Price')
                 ->addMultiOption('0','No Preference');
        foreach ($this->_settings['pricerange'] as $price) {
            $minprice->addMultiOption($price,'£'.number_format($price));
            $maxprice->addMultiOption($price,'£'.number_format($price));
        }

Which produces:

Minimum Price

No Preference
Maximum Price

No Preference

$this->_settings['pricerange'] array is set from application.ini via a bootstrap method, storing them in the registry.

View is set as follows (incase that helps):

$view->setEncoding('UTF-8');
$view->doctype('XHTML11');  

Simply omitting the £ the option label etc are set correctly.

I've added a test case for this, and, quite simply, am unable to reproduce the issue. Most likely, it's a problem related to encoding of the script and/or your web server.

As per your suggestion about encoding, removing $view->setEncoding('UTF-8'); from my bootstrap gets this a step further, but results in:

No Preference�50,000�100,000�125,000�150,000�175,000�200,000�250,000�300,000�400,000�500,000�750,000�1,000,000�2,000,000�5,000,000

View is set up as follows:

protected function _initDoctype()
    {
        $this->bootstrap('view');
        $view = $this->getResource('view');
        $view->setEncoding('UTF-8');
        $view->doctype('XHTML11');  
    }

The app follows almost to a T the quick start (in terms of structure, the default layout etc), can you give me any pointers in order to get this resolved?

Thanks

Just incase someone else comes across this, I found the cause of the problem outlined above, which as rightly said by Matthew Weier O'Phinney isnt a bug in ZF after all...

The issue is caused by Zend Studio For Eclipse, when run on a mac it defaults to using a mac-roman character set, this is the sole reason seemingly valid code was producing this problem, converting the scripts in question to UTF-8 corrects this problem