I wonder if something nasty has crawled into your machine. Grif has more scans for you at link.
In the last two/three weeks emails sent from my Aol to Ntlworld addresses have not been received. The Aol address book appears to have been corrupted. In the address of the recipient between n and t of ntlworld a non-printed character has been inserted but I'm unable to find out what it is. This may account for the non-delivery but the mail has not bounced and so I was unaware of the non-delivery until just a couple of days ago. I'm also not sure if only Ntlworld accounts are involved. Suspiciously just recently most of my saved email was deleted and I had to sift through the recently deleted email and manually restore the important stuff. This happened twice. My virus checker (Microsoft Security Essentials) didn't find any viruses. This may be unrelated to the current problem. I'm beginning to think that I must have a virus or something rather than it being an AOL or Ntlworld problem. Has anyone any ideas?