readln() doesn't stop to read the input.

[jonaspm via Digitalmars-d]

module main;

import std.stdio;
import std.string;

int main(string[] args)
{
      int resp;
      char[] p, q;

      writefln("MENU DE OPCIONES");
      writefln("1) Modus Ponens");
      writefln("2) Modus Tollens");
      writefln("3) Silogismo Hipotetico");
      writefln("4) Salir");

	do{
	    writeln("Introduce la opcion que deseas: ");
	    readf(" %d", &resp);
	}while(resp<1 || resp>4);

	write("Write p:");
	readln(p);  // This is skipped. ¿?
	p = chomp(p);
	write("Write q:");
	readln(q);
	q = chomp(q);


      writeln("p: ",p); // Doesn't write anything.

      writeln("q: ",q); // Writes what you typed in the keyboard
back on readln();


	return 0;
}


This is the entire code.
Environment:
Windows 7 Home Premium x64
IDE: CodeBlocks 13.12
Compiler: Digital Mars D Compiler