Yep, issues here, too. FWIW, I'm not using Berlin WW but Berlin Strings and I'm having issues with it.
More specifically, I think that some Kontakt scripts are incompatible with one another. I was having CPU and hard drive spikes (resulting in pops, cracks and audio dropouts) from playing a single note of Symphobia pizz strings. After doing some non-scientific tests, I realized that Adagietto and Cinematic Strings didn't like being in the same metaframe. Berlin Strings is also acting up when mixed with other libraries.
Note that I don't mix different libraries within a single Kontakt instance, which is all the more worrisome.
Unfortunately, I wasn't able to roll back to 5.3.1 (I regularly batch re-save libraries, which creates brand new Kontakt instruments, and prevents me from opening them in an older version of Kontakt).
I'm on a fast MacPro with SSD drives, 64go of RAM, OS 10.8.5, and run all latest versions of VEP, Cubase and (unfortunately) Kontakt.
Edouard