[fw-gdata] namespace error while editing spreadsheet row

Hello,

I'm using PHP Zend_Framework to manipulate spreadhseet in google docs,
reading works ok, but i'm getting xml namespace error when i try to edit
the row.

The problem is with the gsx namespace, for the first column, the value is 0,
and php will not accept such name <gsx:0>, the local name must not be
only numbers.

$query = new Zend_Gdata_Spreadsheets_ListQuery();
$query->setSpreadsheetKey($spreadsheetKey);
$query->setWorksheetId($worksheetKey);

$listFeed = $this->getService()->getListFeed($query);
$oldEntry = $listFeed->entries[1];

$result = $this->getService()->updateRow($oldEntry,$newData);

And that results in:
PHP DOMException: Namespace Error in
/srv/www/htdocs/magento/lib/Zend/Gdata/App/Base.php on line 211

PHP is 5.2.6 and ZF version is 1.7.2
The getService() returns Zend_Gdata_Spreadsheets instance, $newData is
assoc array (column=>value)
In the spreadsheet, columns do have headers, but the $oldEntry->_custom
holds both named and unnamed(with numeric indexes) entries

This can be easly replicated with:
$doc = new DOMDocument();
$el =
$doc->createElementNS("http://schemas.google.com/spreadsheets/2006/extended","gsx:0");
resulting in the same Namespace error.

Any ideas ?

regards
PiotrN

--
best regards
Piotr