An odd thing that happened to me yesterday with the PostgreSQL ODBC driver (psqlODBC) v9.3.400. It wouldn't let me insert a string longer than 255 characters long into a character varying field into a local v9.4 database on windows using a recordset update. I didn't have a problem pasting it in via pgadmin. Altered the field to text and the problem went away.
I've a suspicion that there is a limit on text in the tens of thousands of characters length too though despite both those fields being essentially the same thing and limitless.