TEXT fields with size > 8190

Why am I unable to store long strings using TEXT fields if the size
of my string is > 8190 chars?

If I try to increase Max LongVarChar to 20000 (in the Advanced
Options box of the Odbc driver) i get run-time error  -2147467259
(80004005) in my VisualBasic 6 application (Ado 2.5).
I use Postgres 7.1.1 (RedHat 6.2 RPM version) and the win ODBC
driver 7.01.00.05 (in the Data Type Option box I have Text as
longVarChar = true).

Is this a Driver related error or am I wrong trying to use a TEXT field
to store long strings (< 64k)?

Thanks, Ivo.