Update_prebinding is slowing my mac

Hi, I'm using a Macbook with 10.4.8 installed with the latest updates. Recently my Mac is taking forever to startup. Everything is fine till the desktop and menubar starts to load. The rainbow would appear then and would take a full minute or 2 before I could access any app. When I checked activity monitor, it shows a process : update_prebinding running, using almost all of my 2gb ram and 50% of my cpu. I was thinking there could be a corrupt file on my system update_prebinding wants to update so it kept running on the same file till my ram runs out cos I have read similar reports in the past.

But its just a guess, any help would be appreciated. By the way, I have already repaired my permissions, clean my cache and done all the maintaining tasks but its not helping.