Stephen,
If you are an AOL user, the recommended MTU setting is now 1450 (I see above that you"ve changed to 1200).
AOL also now prefer you to set your router to PPPOE (from PPPOA) and LLC (from VC).
Since their merge with TalkTalk, they"re also issuing some customers with new yourphonenumber@dialbb.com usernames. This seems to give greater connection reliability.
Hope this helps.