CUPS Web interface hangs when trying to add a printer with Firefox3

Using Firefox 3 on Hardy LTS :
* Connect to CUPS Web interface (SSL) httpS://127.0.0.1:631
* in Administration clic "Add printer"
* give a name and select device
* enter an URI
* select Make/Manufacturer and clic "Continue"
Browser will never show the next page, it will hang indefinitively.

Any idea ?