Dynpro UI Elements in FireFox

The problem is that the UI elements like Dropdownbykey and InputField with bind data type date.

This above elements looks difrent like in IE. They look as if they did not have a point of selection.

The problem occurred after upgrading the SAP NW Portal to version 7.31 SP 17.

Previously issue does not occur.

Details in the attachment.

Thanks for the reply and sorry for my english

Regards

Jarek