Sorry, new to this. I am using Premiere Pro 5.5. This is a clean version, no recent updates or external codecs. This is also on windows 8. I just discovered multi-camera source editing while watching lynda.com and this is such a perfect feature for me to use while doing some stuff.
I've never had any problems with multicam and I use it many times a year both with 5.5 and 6. Which 'steps' did you actually take? Sync-ed all clips in one sequence then right-clicked on that sequence in the Project panel to select "New sequence from clip", changed the name to something appropriate, opened that new sequence and finally right-clicked on it, selected "Multicam" and enabled it? Something like that? Finally you would then open the Multicam window.
Here are some screen shots. When I do what you said and enable multicam on the window tab, just one of the clips shows up. When I was watching a video, they told me to set the in points, then once that happens, I can right-click on the videos I have selected, then a "Create multi-cam edit" will be on a drop-down menu. Here are some screenshots.
That video was explaining the new way only available in CS6.
For all version of PP, there is a second (and I think, still preferable) method of creating a multicam edit.
1. Create a 1st sequence. Add your clips and sync them up.
2. Create a 2nd sequence. Nest the 1st into that.
3. Right click that nested clip and choose Enable Multicam
4. Hit Enter to render the audio.
5. Open the Multicam window and edit.