Ryzom

I had the same thing, upgrading my Linksys router to the latest firmware solved it. So you should make sure your firmware is really the latest, otherwise I don't know...

I've figured out this one but I thought I'll leave a trace to help out anyone else having the same problem. Each time the game patched itself, it never restarted and when restarted manually there were some errors saying "checksum error" or "checksums don't match" or something similar, and Ryzom then ...