Yes, it does seem to be missing from the Fuzztastic Plug In as well. This is a little easier to see, as the FX involved in the chain are shown. It says that TH2 Sonar should be part of the FX, but is shown in brackets, which I assume means that it is unavailable.
So I'm a little more confused now, as next to the Fuzztastic Plug In there is another Plug In called Fuzztastic Platinum Only Version which shows that it has TH2 producer as part of the FX chain. TH2 Producer is certainly present in this FX and works OK. What's going on there?
Curiouser and curiouser.
OK, I'm off to tech support to see if I can have them take a look at it.

Sorry to bump this, I've sent a report to tech support and received the automated reply but haven't heard back from them. If nothing by next week I'll re send a request for help. I'm sure it's system specific but I can't for the life of me work out why this would happen.

Your patience is exemplary 
 
This is sufficiently unusual that I'll try to expedite the process.

Thanks Craig. It's ok, there's lots of other stuff to work on. I did mention in the report that you had suggested I send off a email.

Sorry for bringing this up again but I've had a few goes at fixing this and I don't seem to be getting anywhere. I have emailed support but as yet I haven't received anything but the automated reply.
I've got a link here to a screenshot I've taken of the Browser in Sonar, and I was hoping someone could take a look and see if this is what is it is supposed to look like. I seem to have two versions of the CA-X Amps to choose from, one of which says CA-X Amps Sonar. Is this right?
https://dl.dropboxusercontent.com/u/30886003/Audio%20Effects%20Sonar.JPG
Thanking anyone in advance.
If this is not right then I'll have something to look at, if it is right then I'll have to look elsewhere.

If you only purchased and installed SONAR Platinum, the "CA-X Amps SONAR" would not be in the list. No version except SONAR Artist and Studio shipped with those FX chains. The other CA-X Amps list is not correct either. The current version for Platinum should read "CA-X Amps Producer." As of Braintree Build 37 this is what the Anderton and CA-X portions of the FX Chains should look like for SONAR Platinum:

Thanks scook, I have only ever owned the Producer version of X1, X2, and X3. I then upgraded straight to Platinum. My first foray into Sonar, after Pro Audio 9, was Sonar Studio 8, I then upgraded to 8.5 Producer, so I think this is the most likely explanation, or at least the first place to look.
 
So I have a CA-X amps install without the moniker of Sonar or Producer, can you tell me if this tied to one of the installs?
 
I would like to get it fixed, it does seem to be the only thing amiss with the Amps themselves. I have now tested nearly all the CA-X amps and the Anderton collection and these seem the only ones affected (although I may not be able to tell). I did see that there was a fix in Braintree with regards to these installs but I still have the same issue.
 
Once again, thanks scook for taking the time to look at this for me. If anyone from support is eyeballing this thread, could you email me with any suggestions as to where I could start. I will fire off another support request if I don't hear from you soon.

Did you install Platinum using the Control Center?
What is the last version of the Anderton Collection installed?

Hi scook, thanks again. I did install everything via the Control Centre, and the version of the Anderton Collection is 1.0.0.10

Most unusual, I would suggest working with tech support.