Ok then the only other thing would be a "clean" install, did you try that?

Cut your runtime from the Poser folder and put it somewhere safe.
Delete Poser using windows, navigate to your Poser folder on your "C" drive [it will be there] and delete it completely.
Re-install remembering to add all SR fixes, see if it runs.
If it does, delete that runtime and replace it with your original runtime, it should work, I have done this previously!
It's your call to do it though, I know it works but I take no responsibility if you do something wrong! ;)

Injustice will be avenged.
Cofiwch Dryweryn.