Is there a chance that it could be your router? My two brothers and I play FFXIV in the same house and we would constantly get R0 for extended periods times and, more often than not,DC from the game. Even when logging back on, not 5minutes later the same problem would occur. I couldn't tell you how many times we would run the 45 raid with our ls and DC'ed not even 3 minutes into run. It was starting to give us a bad rep lol.

We did some research and found out that our original router, the AT&T 2wire with a built in modem, and discovered that while ok for web serfing, it was a steaming pile of crap for online gaming. After we upgraded like about a month ago, we've never had an issue with R0 anymore.

Not saying that your router might be the problem but it is definitly worth a look