I've had luck using different versions of logic. You also might try
opening a new song and importing stuff from the old song into it.....
Thanks for the many suggestions! I appreciate the ideas. That website is a good resource. I have also talked to apple tech support, and already done many of those things such repairing permissions and rebuilding preferences, updated to tiger and the pro app package, plus I keep all non-music things off of that hard disk, including AOL, Excel, etc. I only have bonafide up-to-date plugs. And I have gotten crashes from Garritan, Battery, Cameleon5000, and CS80, so I don't think its unique to any of them. It seems that those crashes come from something to do with ram usage because of opening a new plug, or freezing or unfreezing something. However, I have had crashes with files which only had a single midi sequence and no audio too. The multiple crashes the other day seem to have come from trying to copy some mdi and audio from an older logic song to a new autoload song - it did this repeatedly and consistently.
I bought a new G5 dual specificially because I was getting crashes on my G4, so that makes this doubly frustrating, after many years of using Logic 2.5 - 6 with virtually no crashes or the very occasonal "Try to save your song" thing it used to do. I also got rid of my Maudio board and use apple's built in audio interface (using an external A/d with light cable in). I installed what I consider to be good ram "Geil Apple G5 specific ram", but the one thing I have not done is to do the hardware test CD on that ram.
I've come to accept it as a "cost of doing business" that Logic is unstable, so I save often never knowing when the next hang up or sudden death might occur.