I'm using 4k78 as well, and there are some strange things going on. I'm guessing as well that there is some debugging code in it. Classic isn't running all that well for me.
In 9.1 though I don't have too many quicktime issues. Every now and then a hiccup but that's really it.
And I can't seem to connect to the server. I can see it in the appletalk zone when I set up appletalk, but Appletalk network doesn't show up in the network connection.
VERY STRANGE!