AOL Email Sends email out on it's own!

Help!  I have been seeing emails going out all on their own over the past few weeks, mostly being returned undeliverable or auto-responded to.  I don't send them out, so I assumed I had a virus or malware/bot.  I was on McAfee so updated it, ran it to death & never found anything.  I have Malwarebytes & Spybot Search & Destroy - ran them both, got nothing.  I updated my Comcast AV from McAfee to Norton IS 2010 and when I ran it, it found 4-5 items, I think they were tracking things, so I got rid of them.  My AOL email seemed fine, but then 2 days in a row I saw that emails were once again sent out.  I have updated NIS & run the quick & full NIS scans, the Malwarebytes, and Spybot S&D - all finding nothing.

 

I don't know what else to do.  I just today changed my password on the AOL email account, so that may help.  Interesting to note that I have multiple email accounts on AOL and only one has been sending out bad emails.  Any suggestions would be much appreciated.  I run Vista Home Premium, Dell XPS, all up to date.  Thanks!!