I find it sweet how you made it appear everything had been running for 6 years and not a thing changed and now you finally bother to mention you reinstalled you OS.
What aMule version are you using? Where did you get it from? Does it say "adunanza" anywhere? If yes uninstall it and install the real aMule.
Thx for your help.
In fact the problem was tricky, I had great problems to understand where did the problem come from. I understood. Finally, the problem did not come from Amule
, on contrary, it continued to be stable. In fact the problem came from inside my kubuntu 13.10, I don't know why, it triggered this filthy Firewall blocking the port of my Amule. Meanwhile, in Amule, I still received the message that Kad was connected perfectly. However, why it was very tricky, and really impossible to understand, sometimes the search run, sometimes no, sometimes it gave a search result smaller than usual, sometimes nothing.
As I have an old Win XP, I tried classical Emule, it run very well, and finally I deducted that my provider did not block port. I tried to launch Emule inside Linux with wine, I saw immediatly that ports were blocked sometimes, and sometimes there were free.
Thank you very much for your help, even though it did not come from Amule software, it allowed me to eliminate some sources.