Wow! Sounds like a horrible predicament. I'm glad I havent experienced it with all I've got. Lol But since I import so many via LW it means I have 2 copies anyway. Although I have 2 HDD's split into multiple partitions to keep eveything separate for certain purposes.

With a G5 you have a DVD-RW right? So occasionally back up what you got. Yes I know it adds up. I know very well. I have over 100 dvd-rw's & over 250 cd-rw's & an external HDD. Aaah disks become a pain after awhile particularly when you want to copy them back onto your comp. It takes 'so'long. An external HDD seems to have been a better idea. And no they don't cost heaps nowadays. By the way dvd-rw's of mp3's play happily on many set-top dvd players with menu's & all. Paricularly if they originated thru iTunes which arranes them nicely. SO check it out & get some of those tunes off your HDD.

By the way whenever you intall new softw on OSX you should do a SAFE start & repair permissions with Disk Utility. See Repair, Permissions & safe start links