Very odd, generally that means that the tar archive wasnt' fully created on the source...
And yes, it iwll list what is listed, the -v flag is verbose, which means it'll list all files as they're extracted. It should have extracted all the files to home/forum/public_html/ubb (from the directory you're in; so if you're in /home/gizmo they'd be in /home/gizmo/home/forum/public_html/ubb).
the reason it's listing the path is that when you tarred them you specified a full path to the files, so it was backed up as paths; you can use mv to move the files to where you want them once they're on the server.