03 Connect locking ITSELF

[LJHCarpentry]

hi everyone. i have an 03 connect that has central locking , and a subwoofer!. if i turn up the bass on my sub, or hit a speedbump too fast the van will lock itself. this also happens if i shut the door too hard. I know of another couple of people that have the same problem but no one knows how to cure it.... any info would be much appreciated. Thanks Lee