Why is email I read still showing up as unread?

For many months now, emails I read still show up as unread. They used to go from a bolder print to less bold, after reading. Now, they do not change at all. Even if I mark them as read, they never change. This makes it very difficult to sort through large amounts of email, and Yahoo seems to have no answers at all. Anyone here have some idea how to fix this? Using Firefox (version 12), system up to date, etc.

2012-11-16T01:42:55Z

Updates don't seem to matter, as it's done this on several versions. Doesn't matter what the home page is, either.

Weird issue. Never had it, then it suddenly showed up.

Still hoping for a solution that works.

Greg Knight2012-11-15T13:46:54Z

Favorite Answer

try updating fiefox to 16,also your yahoo page. try making it your home page. g luck.

Jedi Jan2012-11-15T22:17:41Z

I am only having this happen when I keep changing from laptop (Windows 7), to Samsung Galaxy Phone (not sure what update there) and iPad2 ... read/delete from one of these and the others do not recognise what I have done. I am using the three most days too. Probably my own fault.