Expired jre native warning dialog is not closed when browser is closed

Testsuite name: N/A
Product(s) tested: 7u10 b17
OS/architecture: Windows 7/x86

Error log file (if present): N/A

Reproducible: Always
Reproducible on machine: stt-70-vbx3

Is it a Regression: No

Is it a platform specific issue: No

Test run log location: N/A
Steps to reproduce:
- install 7u10 Java
- set date to +~5 years
- open a page with applet in browser
- native warning will pop up
- close the browser
- popup will remain - that's the problem

minor issues with the remaining popup:
- another instance of firefox can't be started until it is closed
- when popup is closed using task explorer, Windows dialogue pops up 'The program is not responding'

Expected: make dialogue modal to browser so browser can't be closed until an option in dialogue is chosen or close it with browser