I’ve found my first OS X Tiger bug (though to be fair a few people found it before I did.
If you are trying to burn a data CD or DVD in Tiger, and you get an error 0x80020025 when you insert the blank disc, the solution is as follows: click on the Apple menu (upper left corner), and select “Force Quit…” From the list of application, choose “Finder” and click “Relaunch” and follow the prompts. Reinsert the blank CD or DVD and it should work fine.
According to the a couple of web sites, apparently there is some caching bug in Tiger which makes the Finder sometimes forget that you have a Superdrive or in my case a Combo drive attached. Restarting the Finder clears up the problem.
And of course, Apple’s online support site offered up no reference to this problem.