That particular feature in the MXCsimple bot is broken big time.. in order to disable it you must remove it via the MXC.ini file and save and then enter the bot choose View > Options > Add-Ons > Choose the mxc file then choose Configure, then remove it from messages there also and save.. restart and it should be gone..
Yes that one is an odd one tho..
It can also be fixed to work right if you place a new code in the text for the command on the MXC.ini file
This one changes the nick for every time a WinMX ID changes meaning every time a secondary user changes primary and will alert constantly but if you would like to have it do this right here is the code to put into you MXC.ini file
Rename=%OLD% is now know as %NEW%