Some people in my linkshell and I have experienced this as well, mostly in The Black Shroud.
We have a theory: It only seems to happen in locations where the servers change hands.
That is to say, the small area where you "zone" into another server is buggy.

I tested this once and had a 90% "raise" rate in the hand-off zone.
The last time I ended up returned dead in Ul'dah, lol.