Oracle OLEDB Provider & CLOB dataType / VB & ADO problem

Hello,

First, I'm french so my english isn't very good

I have a problem with Oracle Clob DataType. When I try to put NULL value to CLOB DataType with ADO, changes aren't not made.

rs.open "SELECT ....", adocn, adOpenKeyset, adLockOptimistic

rs.Fields("ClobField") = Null ' In this case, the Update doesn't work

rs.update
rs.Close

This code works if I try to write a value which is different than Null but not if is equal to Null. Instead of having Null, I have the old value (before changes), the update of the field doesn't work.

-- 
Stéphane DOUSSIERE