Please help re backend message type 0x50

Hello, Could you please help me with my problem. I am currenlty implementing somewhat of a proxy. Meaning, there will be a lot of sql queries doing at the same time. Every URL address will be check whether it exist in the database. After opening a lot of sites, suddenly i receive a "backend message type 0x50 arrived while idle". Please reply as soon as possible because we have a deadline for the project. Thank you in advance.

By the way i am using postgres 6.4.2 running on a Pentuim II-350 with 64 Megs RAM

Donny Ryan Chong