Most data corruption can occur due to powere outages or surges when trying to enter records or transactions within the FW Office project. Using backup battery system and power surge protector, can aid in this issue.
I cannot give exact issues on why this happens in other instances. I recommend that you contact our Support Department at 800-282-4103. As long as you are using the current FW version and a Update Service Plan, a Technician can setup a case and send you upload project data instructions so the data can be ran through a Data checker to see what files could have corruption. Most of the time we can find that files in question, run a Table Repair and can fix the issue. However, if the corruption is more then a Table Repair can correct, then the project data gets escalated for further correcting, beyond a Table Repair.