Recently a farm that has been running fine for many years has developed a strange symptom. Whenever a user opens up a calculated field in order to edit the formula/name/description/whatever the formula for that field has the square brackets removed from all of the field references. (i.e. [Title] becomes just Title) If the user clicks OK, they get an error that says something like "a column with the specified name does not exist" and it doesn't save the changes.
I've tried creating a brand new Team Site and added a brand new calculated column to the site and it exhibits the same behaviour. It is a nuisance since the user ends up having to re-enter the formula's corrected field references each time they edit the column. The calculated formula functions properly in the list, it just freaks out when you try and edit it. I've scoured the logs and can find no related events. SharePoint just seems to spit out the wrong value when prepopulating the formula on the edit form for calculated columns.
Has anyone else ever seen this behaviour or have any idea even where to begin to look for a solution?