ZBrushCentral

Zbrush 4 freezes when Extracting polygons

Hi,
I recently changed my OS from WIN XP to WIN 7 (64-bit) and am having problems with Zbrush 4.
The program freezes everytime I mask and try to Extract any polygons.
Its really annoying and would appreciate any suggestions how to solve this problem.

Here is the info about the problem (its in Slovene language so sorry about that):

Ime težave: AppHangB1
Ime programa: ZBrush.exe
Različica programa: 4.0.0.0
Časovni žig programa: 4c5fc9ef
Podpis neodzivanja: 4c0b
Vrsta neodzivanja: 0
Različica operacijskega sistema: 6.1.7601.2.1.0.256.1
Področne nastavitve: 1060
Dodatni podpis neodzivanja 1: 4c0bfad0574fcd81e95aad1204474d0f
Dodatni podpis neodzivanja 2: f1d9
Dodatni podpis neodzivanja 3: f1d980051a30e4c7774a4c57baf05020
Dodatni podpis neodzivanja 4: 4c0b
Dodatni podpis neodzivanja 5: 4c0bfad0574fcd81e95aad1204474d0f
Dodatni podpis neodzivanja 6: f1d9
Dodatni podpis neodzivanja 7: f1d980051a30e4c7774a4c57baf05020

Hey, i am experiencing the same problem with the extraction of polygons. Did you or someone you know ever figure it out? And how?

Greatly Appreciated.