Marcick,
I'm afraid I can't help much. I tried to get PBP3 integrated in MPLABX but couldn't even manage to get that working. But anyway, have you seen this page? There's a topic about installing the ICD3. Unfortunately the page doesn't exist but perhaps you can find some other pointers as to where the problem might be.

Ioannis,
Out of curiosity, I wonder what MPLABX can offer more as na IDE.
Well, compared to MCSX, here are three things that I personally would like to have (and that MPLABX offers).

* Source level debugging
* Code folding
* Version control

But, as I said, I couldn't even manage to integrate PBP into the thing so until someone more intelligent than me writes a step by step guide I'll stick with MCSX.

/Henrik.