FileMaker 6 client crashing-Mac OS X 10.5

[ComputerGuyCapeGaz]

I am having trouble with a client crashing that is possibly unresolvable, but I want to give it a shot. I had to upgrade the user's machine to Mac OS X 10.5.x in order to support an unrelated application. FileMaker 6, accessing complex databases hosted by FileMaker Server 5.5 crashes at random times and especially when printing large monthly reports/invoices. (The print job can be hundreds of pages.)

When it crashes, it simply disappears from the screen, like "Poof!" Other users are not affected, and the database is not damaged.

I KNOW we have to upgrade, but that is several months in the future. It is a complex custom database that is tied in with Quark xPress xTensions which also have to be rewritten. The upgrade is definitely in the future when the database designer is ready to make the conversions of our heavily customized solution. In the meantime, our business manager is experiencing these crashes. I might have to consider an alternate startup disk for her when running monthlies, but I would like to make it run a little better without doing that.

I have a few other clients running new Mac Minis with FileMaker 6, and I am not getting complaints from them. The Mac Mini's are running Mac OS X 10.5.x or 10.6.x. I will ask around when I am on-site later today. Just because I haven't had complaints, doesn't mean it isn't happening.

Thanks for any insight.