OK, making the leap to Numbers, and finding there is a definite learning curve despite the fact that I've been playing around with it for some time now. Here's the latest adventure that has my sense of self worth in a state of disrepair: Using a large database (again, the pre-1960 ballplayer batting statistics, very straightforward), it was time to do a few simple sorts. So I thought, why not create a duplicate of the file (Edit/Duplicate) and do the sorts from there, because that will prevent any unnecessary/accidental errors to the original. So that's what I did, and all was well as of Friday evening.
Then I opened the file last night and found that the duplicate file I had so carefully arranged (with roughly seven) different sorts had gone awry. The first sort was missing most of the names I'd had listed. There were gaps in the entries all over the place. Where I had comment boxes, long pointer lines were now attached, something I would never have done manually. It's impossible to make sense of most of it; thankfully there were two sorts that did not seem to be affected; it's the data toward the top of the page that is completely messed up. What seems strange to me is that I did not cause this.
So I'm left scratching my head. What went wrong? Am I wrong to expect a duplicate file saved along with the parent file and expect it to stay the same? Are duplicate files inherently unstable? I think from now on I'm just going to have to save everything to my flash drive because, sadly, I just can't rely on my Mac anymore.
Would love to hear if anyone else has ever dealt with this type of data loss or of any theories behind what may have happened to corrupt my file.