I am experiencing exactly the same issue with AOL pLatinum. I also tried (unsuccessfully) to use port 587. I have had to accept defeat. It appears that I am going to have to change ISPs which is annoying because my AOL screen name has been in use for many years now and and all my non work contacts use it.
I keep hoping that some IT genius will find a way around this, but I think we have been truly stoffed by AOL this time.