I am unable to sign with Digital signature using a .PFX file. The button does not appear.

When I try to sign with a Digital signature using a .PFX file, the button to select the signature does not appear. I have JAVE SE 7 U11 platform in my add ons and JAVA Consol 6.0.33 and 6.0.35 in my extentions.

This problem is not encountered in Crome or IE-8