AMD 64 bit support in ubuntu

[H.S.]

Hello,

On a 64 bit AMD processor based system, are there any limitations on
installing the 64 bit Ubuntu version in terms of availability of
packages (specially multimedia)? In other words, are there any
relatively common packages which are not compiled for 64 bit version?

I am going to download Gutsy DVD for this. If there is no difference at
all, I will just go for the 64 bit version, else for the 32 bit version.

thanks,
->HS