Installing 4.0 on OS X gets error 565.1994

[Dar Scott]

I realize this is an obscure error and folks here might not know, and  
even Rev support thinks it unlikely for people here to know, but I'm  
running out of ideas.

I'm trying to install the current Revolution 4.0 on a simple OS X  
10.4.11.  I tried both installers.  As soon as it gets to  
"Installing..." it jumps to "Cancelling...", spelled with two Ls.  It  
hangs.  I click cancel (an L drops out of the spelling of canceling)  
and I get error 565.1594.

I have several earlier versions installed as well as a couple  
versions of Rev Media.

I welcome any ideas on what I might try.

Dar