Rebel XSI shooting overexposed in auto modes

[RebelXSIFt.Worth]

I have a friend who is not on this site that has an XSI and is going to be sending his camera back to Canon to be checked. When he shoots in the preset modes which auto-focus most of the shots are overexposed, but when he shoots in the creative modes...av,tv, etc...any of the other modes like these the exposure turns out fine. Is there anything he can adjust to help bring the exposure down in the auto modes or will he have to send it to canon to have it corrected. He has already tried the "reset to factory settings" and that did not help at all. I appreciate anyones reply that might have some helpful input. Thanks

[AndrewCCM]

Does the XSI have ALO (auto lighting optimization)? If so, turn it off. However, those darn "creative" settings really have no real purpose if you ask me. Worst case, use P mode.

I am a little confused by "Preset modes which auto-focus" however? All modes auto-focus.