Read the manual... it has very specific instructions... basically with AEL you're forcing the camera to lock exposure.... AEL = automatic exposure lock... with any exposure mode - matrix, centre-weighted or spot metering, when you press AEL, it simply locks the exposure so that when you recompose, the exposure is kept the same...
For example... at ISO200, the camera reports f/5.6 1/200 s... if you keep the shutter button half-pressed and now move the camera to point at another scene, the exposure will change... maybe you point at a darker area, then the camera may report ISO200, f/5.6 1/100 s...
Now if you did the same thing initially and then pressed the AEL button (you could hold onto it or change it to toggle mode) and then shift the camera... you will find that the shutter speed will not change... you have locked the exposure of the first scene that you metered...
This is useful in scenes where you have extreme exposures of light and dark and perhaps you want to keep the highlights and don't care of about the shadows...
So what you report is not at all surprising since you metered the scene and then lock it and then take a picture of the same identical scene, so the picture looks the same... If the scene is flood lit so that it's very well and evenly lit... you also won't see any change to the exposure settings as you shift the camera about... you need to have a large enough change in lighting before you can see the exposure change... try it out...
