It seems that the latest PowerDVD builds (2430 and the latest update on the site 2521) have a few problems.

Ealier builds would nicely install and also register the CL264dec.ax codec (and some other related codecs).
But in the latest builds this does not successfully happen.

The result is that AVCHD and also any other X.264 files don't play (you get sound only).

When you nomally register a codec (command: regsvr32 codec.ax) you will get a response from Windows about the successful registration.
In the latest builds this does not work and this probably explains that the setup also did not register them correctly.

The CL264dec.ax file from the latest builds is half the size from my original build of PowerDVD 8 Ultra. So I'm guessing there is simply something wrong with the file.

Unfortunately I can no longer activate my original build with my original CD Key and Cyberlink support gave me a newer build in which the Activation did work, but here I have this problem with the X.264 codecs.

While waiting for an answer from Cyberlink support, I thought of posting it here to see if others have seen or experienced the same.