Hi Andus,
As I currently have two versions installed on my PC (a VDI really) albeit versions 6.5.1 and 6.10.5, I assume the short answer would be Yes. It is however a tricky business with the different databases, so I hope someone can explain how this can be done without messing up the database for one or both of the versions.
Happy coding!
Paul, Sweden
(By all means, do not mark this as the best answer!)