Just started using Fedora Core 5. I installed it a couple of weeks ago, but have been working a lot and haven't played around much with it. I decided I needed to install flash and downloaded it from Adobe. I untared the file and followed their instructions, but it didn't work. I also tried issuing a "yum install flash-plugin", but that failed to actually download and install anything. After searching the internet, I found the answer. I had to add a new repository and then yum would work. Went into /etc/yum.repos.d, created a new file and entered the following text and then yum worked like a charm:
[macromedia] name=Macromedia for i386 Linux baseurl=http://macromedia.rediris.es/rpm/ enabled=1 gpgcheck=1 gpgkey=http://macromedia.mplug.org/FEDORA-GPG-KEY