This is most likely a hardware issue, not an ASL issue.
While this may or may not be your issue, my first node I ever set up, randomly transmitted UNTIL I changed from a CTCSS to a DCS tone. No problems since. From the little bit of reading I had done, it would appear the node was receiving interference from another source in my radio room.
This is why I use COS and CTCSS/DCS, this way it takes 2 signals to activate the node. Plus if needed I can command the system to go COS only for open use in a emergency.