don't forget that for the problem to happen you have to add new fields in the structure and those new fields have to have the same name except for the last digit and be at least 10 car long (ex.: Code_typas_depar, code_typas_inte1, etc...) and then physically move that new field into the structure. Granted it's not something you do everyday, the problem is more that it can really mess up your data if you're not aware of it.

-Ben