Date funny in SQL*Forms 3.0

A strange bug has crept into one of my forms which I don't really understand. A field is defined to be a DATE - a DATETIME in Forms. Almost always repeatable, the day, year, and time are all updatable, but if you change the month, it magically changes back to what it was when you leave the field or commit the record.

I ran it in debug mode and there weren't any triggers reported as being fired. Pretty odd. Any bright ideas?

SQL*Forms 3.0.16.12
RDBMS 7.0.15.4

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