wine users - Jan 2011 - dramatic slow diskperformance

Hi all, 

I'm using Wine for a MotionCapturing Application (Qualisys). Although
it's a quite recent application, it works well (I tried only data processing
so far), but when I try to save a dataset (~180MB), it takes about 20 Minutes
(!!) on my Computer. When I use it under VirtualBox (it does not run nicely
there because of OpenGL), saving takes about 20 seconds.

When I look at "top", I see that "Qualisys.exe" takes about
80% CPU, and "wineserver" about 20% CPU. (I have 2 cores, so 200%
would be the limit).

What's wrong? And how to fix it?

best, 
 Kenny

Edit:

I'm using Wine 1.2.2 on Ubuntu-10.04 64-bit.
(Does this has anything to do with 32/64-bit?)