If you are into troubleshooting (and given that you are here at MacFixIt, it's likely that you are), you'll find a wealth of welcome goodies in Mac OS X 10.5 (Leopard). If I were to make a list of ...

"On my Mac intel mini Toast 7.1.2 will not burn DVD-R discs, errors out with a message 'could not record because of a Mac OS X error' ---- plus this 'Result Code = -13780'" Richard Stout adds: ...

Pay careful attention: When you hear the Mac start-up sound as the computer gets ready to launch, hold down the Shift key. A gray Apple logo screen will appear – when it does, release the Shift key.