[Pan-users] Is this normal behavior in PAN?

[Rick Barry]

In 2 groups that I am subscribed to, they are a couple of threads that are
extremely long. When I get new headers for the group, it will show x
numbers of headers, yet when I open the header pane, there will be only a
few of the new headers. The missing  new headers are always in these
extremely long threads, but do not show unless I turn off the "match only
unread headers" button. Then they are shown in the thread, the thread
itself is underlined and the number of new headers for the thread in
parenthesis as you would expect.

Using PAN 0.132 on Ubuntu 8.04.2