Quicktime/FCP compatibility problem

I heard somewhere awhile back that a certain version of Quicktime might pose a problem with FCP 6. If that's so, would love to know the actual facts.

I'm currently running FCP 5.1.4, with QT 7.2, on OS 10.4.9 (on a dual 2.0 G5). And that all works great. But I just bought the FC Studio-2 upgrade, and want to install FCP 6.

I'm not going to Leopard just now, so my questions are -- before I install FCP 6, should I:
-update the OS to 10.4.11 (or leave it at 10.4.9)?
-update QT to 7.4 (or try to leave it at 7.2)?

Thanks.