I was just messing w/ some of the new presets included w/ version 2 of Z3ta and I noticed how many many of them were clipping badly. (Obviously, I'm talking about pre-fader clipping, yes). Not just by 0.x here - the meters in my DAW register overloads of as much as 4 or 5 dbs at time. And it's not just ONE preset, but, quite a lot of them.

And between that and the authorization issues w/ Zeta, this makes it impossible for me to recommend your products to my peers. Like the legendary out of tune samples in Dimension, it makes the product look amateur and unfinished. - Of course the user can turn down the fader on the instrument - but what does it tell me about Cakewalk that they will release out-of-tune instruments and clipping synths? If they can overlook such obvious things...

And lastly, I've had to post this using Firefox, because these forums are falling to ruins and I get a new random issue every day which I'm chronicling in a Test thread in the Coffee House.

Personally have just started to use Dim Pro and Z3TA 2. Not having any sound issues that you are. I've actually been very surprised and pleased at the software. Much more than I expected.  I also use the Garritan World Library which uses microtuned samples and some instruments can contrast the DimP in that way. But like I said, I really have just started using it (just over a month or so). What do you think causes it? By chance, would these new sounds be the Free Mutant Pack? Brcause I am having problems with Z3TA bring those up at all so far. 
I do also have issues daily with this forum and often get "Cakewalk.com is not responding" messages though.

If you're using Zeta, browse through Factory Content patches. There are many patches in pretty much every category which exhibit the behavior. Leave the fader in Sonar's console at its default position. You should see (and hear some clipping soon). For example, in the Hard Leads category, whoever "sound designer" BC is (patches w/ the initials BC at the end)he has created a bunch of patches that severly clip the meters, sometimes in excess of 6 db. How someone could NOT notice that while designing the sound is beyond anything I can understand, especially when they have access to a big LIMITER button right above the master fader in Z3ta. Note that, the opposite is equally true - a lot of the patches make excessive (compensatory?) use of the limiter.

Factory content is what I've been mostly playing with. I will definitely look closer for this and especially at the BC patches.

BTW, using Firefox and it seems to work better so far. I have noticed several of the sites I go to have problems since I 'upgraded to IE9' on this computer.

I'm guessing that Zeta is marketed primarily towards people who are into aggressive dance music genres - hard, noisy and LOUD and where actual sound quality is sometimes secondary. Obviously, someone mixing his new song on DJ headphones may not fully appreciate the artifacts, noises and unwanted distortion. Simply considering how LOUD Z3ta is (even the old patches - the limiter is on and heavily active on a lot of those patches) may be an indication of that.

And, FWIW, I love loud aggressive music and I don't mean to put the genre down as a whole. But aliasing, clipping and other artifacts don't always work for me, and I don't believe that louder is better.

Did check it out again and heard what you are talking about, Especially the BC patches. I think you're right about it being marketed to DJ/House styles. To be honest, I thought that from the beginning and was just skipping over the obtrusive noise patches. And I tend to turn off the arpegiators so I can hear the true timbre/character of the patch. It's not my go-to synth but I like it's character all the same for certain things. Lately my focus has been on Alchemy, but Z3TA has a different quality. I do agree they give you examples of patches and may be best for other types of music, but I rewrite what I can and dump the rest anyway. Thanks for the suggestion to check it out again.

rapture does this on several patches as well - even with the limiter on.  nearest i can figure is that the delays in the patches are processed after the limiter, and they build up in the track and cause clipping.  kinda weird.