Without even taking my nap I tried the 4.0.3 fresh install (and noticed the appropriate renaming of the 4.3.1 Release Candidate) with no problems. Literally smooth as a baby's rump. Let the adventure begin!
My two suggestions (that would have helped me)
1> Release Candidates, Betas, whatever you want to call them, put them somewhere else i.e. a developer download page. Boobs like me will come along looking for the latest version to evaluate without reading forums to know which is the best version, or eval version, etc. I just want to look at some stable code.
2> Some better troubleshooting or logging needs to be done. I'm a developer, and I stink at writing that stuff in to my code because it just isn't fun, but as soon as something is messed up I hate myself. I honestly still don't know why 4.3 failed for me since all the errors pointed me to my connection string (the same one I'm using now), but I'll never know based on the error logging that I was looking at.
My rant is over. Thanks for the guidance and place to vent. Now it's module writing time.