Thank you, Yoc, I am doing my best.
Jcolag, I am using Okular to display the comics and unrar, gzip, bzip2, unzip, and zip (a Linux version of pkzip) are installed as helper applications. Okular uses the one it pleases to open the archives (in a manner similar to the way Firefox uses Add-ons to enhance its capabilities), so I do not know what is being used at any given time, although unrar is almost certainly being used for the .rar files. Also, thank you for mentioning the file command.
In an effort to see what is going on, I booted into a different version of Linux today (I am running Fedora 10 now instead of openSUSE 11.1) and each file could be opened in Fedora regardless of whether the file extension was .cbz or .cbr