Question : Deletion of record - But HOW ?  Very odd.

I don't expect a solution to this one!
I am just throwing out there in case somebody is phychic!

I am a fairly basic user.
I have a master table with about 400,000 records.
I have set up a form which when you click a button generates a record in transaction table. (One to many : Master to transaction).   All very simple stuff.

However, while the above works when I test it something strange happens with live users.
Somehow (!!!) when I check up on their work. - they are DELETING the record in the master table whilst also generating a transaction.

There is NO delete in my simple VBA.
I have NO idea how these records are being deleted.

I know this is very little to go on but any thoughts would be appreciated.
I do not have the code with me as it is in work and I will not be able to get to it for a while.

Answer : Deletion of record - But HOW ?  Very odd.

Is this happening with all your live users? Would you be able to watch them while they're using the system so you can work out what it is that they're doing differently from what you did when you tested it?