All,
I currently have a case open with Microsoft around call quality issues when utilizing Vista and MOC. These issues can occur with a Catalina or any other device that is connected to your PC. We have found some interesting information in the process of troubleshooting and hopefully soon there will be a fix.
In the mean time I’d like to request that anyone who is having similar issues (lost syllables, clicking or popping sound, etc..) when using MOC email me with details of what they are seeing including build info on MOC and the machine. My email address is Kevin (AT) this domain. I look forward to hearing from you!
The Lync Guy's Blog 
Hi,
We had problems with the audio quality Catalina and Windows XP.
Have you had problems like this on windows XP & Catalina?
Thank
Hello Ricardo,
The solution/workaround proposed in this post is for Vista and MOC only, working with the clients support team and MIcrosoft we were able to determine the root cause of our audio issues on Vista with MOC to be boxing (startup boxing) malfunctioning. We also tested XP (all SP’s) and WIndows 7 (RTM) without experiencing the issue. That being said there are still other things that could cause the same problem for different OS/Client combinations.
May I suggest the following tests:
1. Remove Catalina and use a non-USB connected device to test – this could be built in microphone and speakers if the machine is a laptop, or an RCA connected speaker and microphone.
2. Test on non PC based client (i.e. Tanjay phone)
3. Disable CState on the affected machine(s)
4. As a test (and only a test) disable any antivirus applications running on the client
5. Remove all non Microsoft services and applications from startup (MSConfig)
6. Test dis-similar hardware (If you use all Dell laptops of the same model, try a different model if one is available)
7. Verify you are running the latest drivers for your network card and USB bus
Please report back with your findings as well as information from the client machines that are experiencing this issue (including Make/Model of all affected machines). I will be happy to assist with this issue as I can. I’d also suggest posting this on the OCS technet forum (link below), there may be other folks out there seeing the same problem you are, in which case we can all help each other.
http://social.microsoft.com/Forums/en-US/category/officecommunicationsserver
Thanks for posting, I look foward to your reply!
-kp