...and use option-click > Compress to create permanent .zip files...
Hmm...Do you have your Option key set to perform a Control key action in System Preferences'
Keyboard prefpane ->
Modifier Keys... sheet (if that even accurately describes what a 10.6.x laptop user sees)?
I ask because AFAIK it's Control- or Right-clicking which invokes the Finder's contextual menu offering the Compress option.
