Just for your information there was another workaround for that about a year ago. It was to reset the Mac's clock back a year to a date before the certificate expired. That allowed the installed to work as it should.
Once again you are demonstrating your deserved level XI status.
I think this whole "certificate" thing is an evil plot ! I can certainly understand that as computer systems move forward, eventually, older programs will quit working. But I can't understand any attempts to intentionally break them.
I'm still using a number of older pieces of software that work perfectly. Perhaps they don't have a certificate stone around their neck. I occasionally use a 10-year-old version of FileMaker that works just great.
Well, you and I figured out some time back that if you want to use optical media on a Macintosh, you have to be Sherlock Holmes occasionally.
( Lately I have been editing HD movies with QuickTime 7 Pro, and using Toast 12 to make Blu-rays. It's so frustrating to go from a terrific piece of software like iDVD to Toast 12. but, it's "all we got!" for Blu-rays. )
By the way, did you know if you create a image file with toast, ".toast" file, that Apple's Disk Utility will burn the Blu-ray just fine ?