I have had issues with dead female pornstars, kinda out of respect for them. However lately I find myself thinking, perhaps it would be ok as afterall, they knew what they were doing and that what they were doing was for adult, mature entertainment and that their sexuality should perhaps be celebrated still by men in whatever respectful way. I mean, surely one of the most complementary things a man could offer one of these women (Like Anne Malle etc) is to be very turned on by the work they left for us with their lives.
It's not like masturbating to ghosts or spirits etc I suppose, afterall, it's merely digitalized, pixilated imagery in which their once perfect forms now immortalise.
I would say yes, it is ok, but try to do it with a degree of respect and a sense of appreciation due to what they did for us blokes when they were alive!