WD 400 Caviar 40GB HDD + Linux firmware

I am trying to find a provider for the firmware for my WD 400 Caviar 40GB HDD for Debian linux v.5.0.6.  If anyone has the answers I would much appreciate it.  I was told by the linux forums to search the Western Digital Site.  I inquired with Western Digital and they said to try these forums or try the Linux forums.  I keep getting the run-around and I am about to drop the Idea of using 2 seperate HDD’s for 2 seperate OS’s.

Thanks for your help,