Media Pro so much slower than Media Expression

i use a macbook pro 2,4Ghz i5, 16GB ram.
i upgraded from media expression 2.0.2 to media pro 1.1.0 and the rendering
of the thumbnail view und media view is so much slower.
the media view of a 16mp jpeg-file takes 2 seconds in full reolution.
in media expression i got the media view instantly.
i tried different settings for the rendering.

Whats wrong? any suggestion?
THX!