Hi Eran,
Just discovered your thread about the Metz 58 AF2. Congratulations, it's an awesome flash, and in my opinion it's the best flash there is today for Pentax cameras.
I have it too, so that makes (to the best of my knowledge) two of us in Israel who have it.
The operating manual that comes with the flash is unfortunately not the best and is missing the chapter on servo mode. Metz posted it separately on their website here:
Pentax: Metz.
I strongly recommend using Sanyo Eneloop rechargeable batteries, along with a good charger such as one of the Maha chargers (I have a few and they're excellent).
Even though I've had the flash for over a year and use it quite frequently, I find that I have quite a lot to still learn on how to use it, especially in tricky lighting situations.