Address changes for all the pupils with the same post code

[Buzz]

An interesting issue we started noticing recently. If you change an address for a student, all the students who live in that road or who have the same post code their addresses changes to the new address you have posted for that pupil.

Can anyone shed some light to why this is happening and what we can do stop this? Our admin ladies have exhausted the blame game as only one person does all the changes on the system.
I have ran a database diagnostics and no errors were picked up

[djm968]

Which MIS system are you using?

[PhilNeal]

If its SIMS we record to dwelling level and attach all individuals at that dwelling to the same address. When you change an address you are asked if you are simply editing i.e. got it wrong or moving. If you move all people that live at that dwelling can be moved in a single go - if that is what you want.