Maybe you could try reprogramming the remote to use a different frequency.

 

Both of mine are DEI (one for sunroof, one for windows) and they both give me issues. It's not the frequencies, they just work when they want.

I've installed countless alarms so I know the install is okay. Past window module installs have all gone the same. I'll never install this type of unit again. Not worth the hassle.

Factory works just fine.

 

I doubt it's your neighbors remote opening your window. These security systems have rolling code transmitters, and the chance that someone elses remote would work on yours even once is like one in a number with a lot of zeros after it. I have a remote window actuators on my SC (Code Alarm), and they work perfectly.