I don't know if we're running different versions of PHP or something but I can't seem to correlate what you say with my results from sample code. is_numeric('fsda342') will return false, it's quite obvious that that string isn't a representation of a number. As for the user input comments, I only wrapped the values in quotes to denote that they were indeed strings rather than their integer/float counterparts.

As for is_bool, I've never had a problem with it and after a quick search I can't see any bugs filed for the function always returning true and it's certainly not expected behaviour. Does anyone else here have the same results?