I was having trouble with this glitch for the longest time, but finally found a way around it. i originally bought a GOTY copy of the game. Needless to say, I traded it in for store credit, and sought out a OG version of the game on PS3. I later downloaded shivering isles via PSN. This re-introduced the vampirism bug into the game. I was furious about it... I decided what the hell, and, when whats her face wouldn't accept my bloodgrass, I deleted the shivering isles expansion from my PS3. I reloaded the game, and sure enough, blood grass was exchanged, and I was no longer a vampire. I wonder, now that I cured the vampirism, if i could go ahead and re-install the shivering isles expansion? hmm...

Just food for thought. I think it would be awesome if Bethesda patched this for the 5th anniversary GOTY edition on PS3.

They did not patch that.