Cannot type a capital C at bash command line. If I try to type a C, the next character is quoted and doesn't print, plus I get an alert beep. I can type any other characters. It only happens with one of my logins. It is probably not a problem in the user .bashrc or .bash_profile files b/c more than one user is using a copy of the same files, but only one of them gets this error. I can type the C in any other shell
I've tried this on a large number of computers, without seeing this problem anywhere. I suspect your local config files (.bashrc, .bash_profile, .inputrc, ...) are messed up. Maybe someone is playing a practical joke on you by loading an altered keymap. (Check your PATH settings - maybe someone put /home/someone/bin in your path before /usr/bin or something - that could cause a perfectly normal .bashrc to mess up...)