next unread mesage, newest or oldest?

hello,
it seems like "next unread message" is looking for the next unread message 
from top to bottom of the mails list.
however the mails are not necessarily ordered by ascending date from top to 
bottom therefore we don't get the next unread message as in the first to arrive 
that we didn't read... (I hope that wasn't too confusing).
the problem arises for me in the inbox folder where the newest messages are in 
the top and "next unread.." is starting from the top resulting in reading the 
new mails before the old ones.
I think a way to "fix" (as I am not sure what was the original goal) this is to 
look by thread date (if there is such a thing)...

thanks for your attention, this should probably was better sent to the kde-pim 
list, though many are subscribed in both.
YB