Doubleklick a row in a ListGrid with Webdriver

Hallo,

I'm trying to double click a single row in a listgrid with selenium webdriver but ist does not work.

for this I used the standartd firefoxdriver and the aciton class wich includes a double click but the driver does not react:

WebElement localElement=getElement("//ListGrid[ID=\"isc_ListGrid_"+gridCount+"\"]/body/row[doclock=||0]/col[fieldName=documentId||2]");
action.doubleClick(localElement).perform();

getElement is a Mehtod wich locates an Element with scLocator and returns the WebElement located when present.