[PostgreSQL] psycopg2 problem with libpq.dll , Postgres 8.1.0 Win XP

Hello.
I was using psycopg2/Python with Postgres 8.0.4, on Win XP.
Now, when I installed Postgres 8.1.0 and was trying to connect with Python/psycopg2, an error occured: "This application has failed to start because lipq.dl was not found. Re-installing the application may fix the problem."
What to do?

Thanks,

Zlatko