Virtual Particles: Positive or Negative Energy?

[Hymne]

I often read that particle-pairs that are created in the vacuum consists of a particle and it´s antiparticle which both have an positive energy that is "borrowed" from spacetime according to Heisenbergs Uncertainty principle.
But when it comes to Hawking radiation one often refers to one of the particle as a negativ energy particle, which is very confusing .
What is true, does particle pairs consist of positive-energy particles or on positive and one negative?

 

[Hymne]

Solved it.. The thread can be thrown away.

 

[Demystifier]

And? What is your answer?

BTW, I am just writing a paper that should resolve the puzzle of negative-energy particles in Hawking radiation. But don't ask me about that before I write it.

 

[Demystifier]

Here it is:
http://xxx.lanl.gov/abs/0708.0729