Yep, just like vanilla skyrim my stage-4 vamp is attacked, even though i have dawnguard. I fast traveled my vamp to whiterun, and it was attacked by the NPC's.

Does anyone have this problem, or is it just me? It seems the dawnguard changes for vampires has affected my vamp character, except it still hasn't removed NPC hostility.

Do you have the orange glowing eyes?

If you don't then the DLC isn't active.

I was attacked once in Riften as a stage 4 vamp, NOT in VL form. I've been to Whiterun as a Stage 4 vamp and haven't been attacked so... not sure if getting attacked was the glitch or not getting attacked.