I have a test site I am building using Joomla 3.4.1, Community Builder 2.0.x, and Kunena 4.0.x - it will be an upgrade to an older Joomla 2.5 site once I am done testing everything.
On the test site, I uploaded and set a new default Profile Pic that fits better with my theme. It works in CB, displaying as the new default when someone does not have their own - So far, so good.
On Kunena, the new image appears in some places properly, but does not appear in others. If you go to:
template.knightrealms.com/forum/index.html
You can see the new default image in the Index for the "Event Highlights" category, and again in the Event Highlights index itself. Yet when you go to a topic, the default image is the stock CB one, and not the new one I chose in CB.
The same issue is occurring in the CB User List - the image being used for profiles w/o an image is not the one I configured in CB.
The default image is attached, below, so it can be recognized in the example above: