I am on Mac with CS5 and have every WA extension plus a few others and have no issue.
So, I am wondering what are your other extensions? Also, one trick would be instead of actually renaming the config file, I think you try opening the extension manager and disabling all of your non-WA extensions. Then enable one at a time - starting Dreamweaver after each one.
One more thing while I am thinking about it... have you downloaded the latest releases from WA which are all certified for CS5. If you haven't downloaded the new versions, that perhaps could cause a problem.