data edits are different than record creation, so that checkbox has no influence.
I would check your auto-enter/looked up value calculations to see if something is triggering off there.
More importantly, do you have a modification user/timestamp field that you can use to determine who/when is editing those records. Those fields are a must-have in most tables, along with primary key, and creation user/timestamp.
You might also want to update your permissions to make sure some users aren't making errant changes.
Mike is right ...
Data edits are not the same as record creation.
What exactly do you men by random?
A little more specifics is really needed here to recommend a solution..
More along the lines of I have this setup and when i do this i expect this but get this.
I have found that if i develop a solid comprehensible question then the solution becomes obvious.
You can always post the file so we can have a look.