Intel X.3.9 Writing large files to drive..need fix

[Jack D.]

A friend with a 24" Intel iMac 10.3.9 250gb drive has the disappearing space / large file problem. When she goes to save something the Disk Full error pops up. When I "Get Info" on the drive it shows 130gb free. I know this has been talked about here but the search didn't seem to find anything. Other sources say it's a log file gone wild and I should use something like DiskInventoryX to find the file(s) and delete it.

I need to solve the problem not just delete the file. Is this something where I should archive and install a new OS or is there a simpler fix? TIA!