Akoustik Piano crashes in KORE and Forte

Hi all,
after hours and hours of trials and reading this forum the last months I hope anyone can help me.
My dream was to play live only with my laptop and a masterkeyboard instead of using my Motif ES. I wonder if I should give it up and sell my whole plugins.

Akoustik Piano works fine in standalone mode. But as I play in a Top 40 band I need much mor than a piano sound.
So I bought Komplete 5, Kore 2, brainspawn forte and a new laptop (Acer Travelmate 7720G, 2,2 GHz Core 2 duo, 2x 250 GB HD, 4 GB ram, vista home premium 32 bit).

Every time I use AP it crashes while switching presets (in KORE) or scenes (in forte). Sometimes only AP can't be heard any longer, sometimes the whole program crashes. It doesn't depend on which piano I use or how many instruments are in the performance (KORE) or rack (forte). Also using Kontakt 3 with the Concert Grand doesn't work. Same crashes. It only happens with the AP sounds. Every (!) other vst works fine, even EP, Absynth, Reaktor.

When I load e.g. the Steinway light of the Kontakt 2 library in Kontakt 3 I have no problems.

I use all updates, I experimented with the dfd setting, I did all the stuff with windows mentioned e.g. on MusicXP. It doesn't matter if I use the KORE controller or my presonus firepod aswell.

Any ideas?
Thanks a lot!
Frank