'false' - boolean interpratation

is there any way that string 'false' (and its variations with capital letters) could be interpeted as boolean of value false? i have xml configuration file that has some switches (true/false) in it. when i use this values in functions that require booleans i get true every time (as string isn`t empty) :/ i hoped that at least with explicit type cast i could go around this problem, but i didn`t help. how about adding this special case to conversion rules? creating if`s around such code doesn`t make me happy at all :] rash