Yes, it switched me to Searinox with the underscore and ghostkill did not switch it back. mIRC has Searinox set as a secondary nickname, when it is not possible to use the primary nickname it switches to it. GKNP didn't change it back to Searinox. The problem is actually reproduceable whenever I manually restart my network adapter in device manager. My guess is it has to do with mIRC not having any IP to bind to. True, adapter resets are not something that can accidentally happen like network dropouts, but still...