lo_import problem under Windows+BCB5

I have a problem, i try to use libpq with Borland C++ Builder 5 
Standard, everything works fine, but when i try to import a large object 
with lo_import it import it, but when i lo_export it the result only the 
original binary file until the first EOF character.

The backend  is a Debian linux, with PostgreSql 7.2.1 .
The frontend is Windows 2000/XP/9x, Borland C++ Builder, libpq.dll 
compiled with Visual C++.

Thanks for your help!

Bistey Csaba