If it´s none stop it can possibly be...
Reason 1) You downloaded somehow a Trojan/Virus whatever, so do a System Scan or try System Restore to 5 days ago.
(happened to 2 people I know in the last days)
Reason 2) You get d/c because of FFXI App.
Reason 3) Your Router has problems.
Reason 4) Got Vista? A friend of mine got for a while after installing FFXI on his Vista PC a few d/c on the first few days.
We changed some settings and it worked well. (Don´t know what we changed though, was a few weeks ago)
Reason 5) If your provider disconnects you every 24 hours and you get first d/c and try to get online again, then you will recieve d/c every minute. If this happens you have to completely log out and start POL again, then it works again. (Happens with some providers and thats why my auto d/c is at 5AM when I sleep for sure)
My guess is Trojan/Virus or FFXI App
or 5).
I would try a System Restore if you did not change a lot on your PC in the last days.