IR Remote code help

I'm using Ken Shirriff's IR Remote library to have a remote control for Lego Mindstorms building set control a car that has tank-type steering.

When I press a button on the remote control, the Serial Monitor displays different codes. Which code for which button?

What sketch are you using? What is displayed when you press the button? Is it consistent? How have you wired your stuff? What type of sensor are you using (link to datasheet)?

I'm using the sketch from the website.

#include <IRremote.h>

int RECV_PIN = 11;
IRrecv irrecv(RECV_PIN);
decode_results results;

void setup()
{
Serial.begin(9600);
irrecv.enableIRIn(); // Start the receiver
}

void loop() {
if (irrecv.decode(&results)) {
Serial.println(results.value, HEX);
irrecv.resume(); // Receive the next value
}
}

When I press two buttons, the Serial Monitor displays these codes:

2AAF9A91
496987DC
895E3D20
496987DC
80604C62
496987DC
C347FB68
496987DC
C981590A
496987DC
80604C62
496987DC
80604C62
496987DC
FFFFFFFF
496987DC
80604C62
496987DC
80604C62
496987DC
80604C62
FFFFFFFF
80604C62
496987DC
80604C62
496987DC
80604C62
496987DC
80604C62
FFFFFFFF
80604C62
FFFFFFFF
28808EAD
FFFFFFFF
28808EAD
496987DC
28808EAD
FFFFFFFF
28808EAD
FFFFFFFF
28808EAD
496987DC
7DF58202
496987DC
28808EAD
496987DC
7DF58202
496987DC

I wired the circuit following the diagram on the website. The sensor came from BASIC Stamp Boe-Bot kit. http://www.parallax.com/Store/Components/Optoelectronics/tabid/152/CategoryID/30/List/0/SortField/0/Level/a/ProductID/177/Default.aspx

When I press two buttons, the Serial Monitor displays these codes:

What does that mean? Are you pressing the buttons at the same time? Or one after the other?

What kind of remote control are you using?

I use the same sensors with the same library without any problems.

I tried different remote controls for TV sets and I think that there are interference. If I move the wired USB mouse, codes appear on the Serial Monitor.