Powerbook not finding Brother Printer Driver

I have a Powerbook G4 running 10.4.8. I just purchased a Brother HL-2070N laser printer. I find posts where others are using this printer successfully with their Macs. However, I'm getting an odd error message.

This is when I double-click on the 'brxubpt11c.dmg' file that is on the Brother CD ROM. I've also downloaded the same file at the Brother support site.

http://att.macrumors.com/attachment.php?attachmentid=61406&d=1162685164

If I select 'ok' at this point, a finder window opens up looking for a location to select. No matter what I select, I get an error message saying I've chosen a location instead of a file.

I've called Apple and Brother, and both are at a loss.

I've posted similar requests for help on MacOS Hints, and MacRumors and so far no one has found a solution.

Thanks in advance for any help offered.

Powerbook G4 1.67g, 2g RAM Mac OS X (10.4.8) 30g 5G iPod, Airport Express, Linksys Cable Modem

iBook G4, 768mb RAM, 40G Combo Mac OS X (10.4.3) 20g 4G iPod, Airport Express, Linksys Cable Modem