Re:Keyless Entry

My niece has a 2000 Nissan Altima GXE, that was purchased from a dealer in Queens,N.Y. She has had intermittent problems, whereby when she locks her car with the remote in the evening, she will find the doors unlocked the next morning.

The car was taken to a local Nissan Dealer, who indicated the original remote was faulty. They replaced it with a new one, only for her to have the same problem. Is there any information that could be furnished in regard to this matter. It is most perplexing!

Would appreciate hearing from you.

Thank you

Mazz