2001 altima gxe remote problem

Hi, My sister in laws car is having a keyless remote issue. The problem that occurs is this, her remote has 3 buttons on it....lock, unlock and trunk unlock. This sounds strange to me but here is what it does. The remote works one second and may not the next but if it is in the car laying somewhere inside the car and there is NO WAY anyone has touched the buttons, her flashers come on and off randomly but no audible alarm sound and the security light comes on. The lights also go off and stop blinking on their own just like they came on. It does this while the engine is running in park or driving down the road. We put a new battery in it but it had no effect. Anyone want to take a shot at this? LOL!! Ive never had a security system in any of my cars so im takin a shot in the dark thinking the remote has gone bad and sending a random signal or something but was just looking to see if anyone else might have any other ideas? TIA.

seen remotes do this before. take the suspect remote out of the picture completely and see if you still have the symptoms, if not, buy a new remote.