Please reread my post, Misha; I've edited it.
> Strangely enough I can boot up an older Core 2 Duo (2GHz) iMac running the same OS X version just fine. And -as far as I can see on the Alsoft web site, it appears that I just have to wait for Apple to release the new startup files to Alsoft.
The version of OS X you're running is of no consequence; the critical factor is that your older DW disc cannot boot your newer iMac. (When did you buy DW as compared to when you bought your Core 2 Duo?)
Note: The current
DW disc will boot your new iMac, but you'll have to buy a new disc to turn the trick; it will be cheaper to buy a backup external HD and run DW from there. (The Alsoft note you mentioned applies only
to the specific Mac mentioned therein.)
> I'm also wondering if DW 4.2 will be able to rebuild the directory and/or defrag?
DW does not
defrag; it rebuilds directories (and does some other inconsequential stuff).
DW 4.2 will work with OS X 10.6.3 on your new iMac, though.
Hope this sets you straight.