trying to use yum to install avi codecs among other things that should be easier to get, i get the error "public key not available for divx4linux-5.0.5-0.1.fc3.rf.i386.rpm" what does this mean and how can i fix it and why, if an rpm depends on other packages, why arent they included in the rpm in the first place???????

It's just means that the RPM isn't signed properly - I shouldn't stop it installing.

Dependencies are often used by more than one package (for isntance, Xine, Mplayer, Kaffeine & Totem might all rely on an MPEG decodeing library). Installing a copy of that library for every package that uses it would waste space, and would result in incompatabilities (for isntace, the MySQL server and MySQL clients [like PHP] need to use the same version of the library to communicate properly).

D

well it does stop it installing, once it says key unavailable it stops and returns me to the command prompt