[X-Newbies] iMac Firmware update problem

[Michael Winter]

It just sunk in that you got the file off a USB key, which is  
probably FAT formatted. The update is probably a "classic" two-forked  
file which FAT does not handle. Mac OS 9 (and earlier versions) had a  
little trick they used to get around this limitation (one fork was  
saved in an invisible file that OS 9 would look for when copying from  
FAT volumes). If that update was downloaded to a PC, or went through  
a PC at some point, that "fork" of the file will be gone. I don't  
know off hand if the download from Apple is in a "PC/FAT safe" format  
or not

-Mike