Mailing labels from mail merge

I'm trying to build a set of "Avery 5160" labels to match the letters I'm printing via mail merge, using the same spreadsheet data source.  When I select Mailing Labels as the new document type, I am presented with a drop-down list of databases.  I've registered the spreadsheet during the letter creation (though it has seemingly created the database multiple times, as it shows me 4 or 5 options with the same name) but when I select it in the labels dialog, it shows no tables and no fields.

Help!  How do I get the "registered" databases to show me the fields and data?

The mail merge process seems to be pretty cumbersome.  Aside from this problem, labels aren't created the same way Letters are, and I had to search and try things for hours to figure out how to insert address, salutation, and other fields manually (I don't like the address block approach of the wizard).  The system seems to think my merge documents are damaged, launching the recovery system every time I open them (see my other post), and discarding the auto-recovery entries doesn't help.  This really shouldn't be so hard to do.

I was contacted off list to discuss this not long after I was able to get the system to work.  See my reply below.  In short, I did eventually get it to work, but I have no idea why.  And the whole experience seemed a bit buggy.

First, I was able to build a merge letter with the wizard, once using an address block and then, after some struggling, I figured out how to add the merge fields directly and NOT using the wizard address block.  (Note that system is not at all helpful when starting with a pre-existing letter - it shifted blocks of text around and basically ruined the letter formatting.)  But then I could not get that system to actually merge the data into letters.  Somehow after closing and reopening that file and de-registering and then re-registering the spreadsheet, the commands for merging to document or printing showed up.  But even then I was still not able to flip through the records to see how they would appear in the preview.  I was able to merge the document to a file, though, and then print that.

Then after similar stumbling around, opening and closing files, de-registering and re-registering databases, I was able to get the merge fields to show up for the labels.  I've now printed the labels.  But again, I have no idea what fixed the problem, and am not at all confident I can do it successfully in the future.

Mail merges are one of the most important aspects of an office suite like this for me.  I really wish it could be made more simple and reliable.

Carl