that's very strange.. i'm using it without problems, make sure to use one macro only for restart km..either the one without the toolbar button or the macro for the toolbar button, both will add the same menu command.. and make sure restartkm.exe is saved in tools folder (k-meleon\tools)
menu entries disappearing is due to conflict between macros or a badly written macro(perhaps missing a semicolon) and the restart macro is error-free..so it's probably a conflict or other bad macro; did you add new macros recently?
incase of a conflict i uplodaed this macro with slight changes (instead of restart restarter11:more unique)
test with this one and hopefully it will work:
(this is without toolbar button)
for restart with toolbar button..i don't know how it works and desga will check it