messages being called "unread" after I read them

[Al Sten-Clanton]

Hi.

I often find that as I arrow through my inbox messages in Thunderbird, 
ones I've read are said to be unread.  Since this just happened, I 
thought I'd ask if anybody else sees this or knows how to fix it.

I'm using Fedora 18, orca 3.6.3, and Thunderbird 17.0.6.  I've seen this 
for a while, though.

Thanks for any help.

Al