A few thoughts...

A book to look into is called "First Person Plural," You can read it here:
http://books.google.com/

My Aunt's best friend is a therapist specializing in DID. The conversations were very interesting. My understanding is that it is only known to be caused by rather severe abuse early in life, so I'm not surprised that someone with DID would also be diagnosed with PTSD. The goal in therapy is to eventually integrate the separate identities.

Towards the end of my time with my first therapist, he began to wonder if I had DID. Sometimes he felt like he was talking to me the 23 year old, and sometimes he felt like he was talking to me the 15 year old.

Around that time in my life was when my traumatic memories began to reintegrate. The experience was kind of like the traumatic images and the traumatic feelings were connecting, and suddenly what used to be numb I could now feel in life. Given that, I don't have a difficult time imagining that DID is real.

I guess my question is how dissociated are you? Do different identities have different memories, or are the traumatic memories accessible to you?