Yeah, I know. The site profile. I remember installing dw4, the studio, and reading that there was a certain order of installation. I can't remember the order, DW first, then Fireworks, or the other way around.
I currently use DW MX. I've had some weird installation problems with this in the past. I would try uninstalling dw. Afterwards go to your programs folder and delete all the DW folders. And re-install it.
I've had a similar problem. This was and still is the fix for me...
When you start MX go first to 'site' shown in the 'files' on the right side of the screen. And change the start up site to any other site than the one listed. (This is currently the default start-up site.)
Close MX and restart. Then look to see that the start up site is the different one you just chose, and if it is, you are ok.
There seems to be something that corrupts the ini file for the current default site, and changing the default site appears to reset the problem 'whatever'.
Your create-site should now work without crashing.