Sounds like your kids have somehow up/down dated you to 3.4, I wouldn't have thought that possible using normal means. IOS50 is the system menu IOS which is used by 3.4, a system using 4.1 would show IOS60 here.
So somehow your system is pointing to IOS50 but has no System Menu v386 to go along with it.
You need to install IOS60patched and then System Menu v450.wad using preloader to launch wad manager, that 'should' fix your problem. I have these files in my mediafire if you'd like to click my signature.