Getting file name as Null from Upload component of Vaadin 7.0.0.alpha* vers

Hi, I am using the Upload Component from Vaadin. And trying to read the file as soon as it is user clicks on upload button. For the same I have implemented the Receiver interface and found that the file name argument for receiveUpload() method is coming as unknown.

This issue is only visible in IE browser whereas it works fine with Firefox. The Vaadin 7.0.0.alpha 1,2,3 jars are having this issue. Whereas the issue does not exist in Vaadin 6.8.1 jar.

Please provide the fix for the same.

Regards, Amit Kale