Problems saving on Pages

I've read several posts about this issue and would really appreciate if someone could really simplify it down for me . . . .(nicely, please!)

I upgraded to Lion OS. I opened a document that I created pre-upgrade. First problem was, it told me the document was locked and I couldn't make changes, that I didn't have permission to do so. What? "The document is locked. If you would like to make changes click unlock." I clicked unlock. Made changes. Tried to save . . .clicked "Save a Version" (this was a new option to me). Got this message, "Document could not be saved, document is locked. Do you want to save anyway?" Clicked "save anyway" and the response was "You do not have permission to change the file." How is that possible when I was the one who created the file? Had to open the document in Finder > Get Info, then unlock the document. Did so. Then the box popped up saying "Document could not be auto-saved, document was changed by another application." I assumed that meant that since I changed it in Finder, I'd have to close the document and reopen it. It wouldn't let me close it without clicking "save anyway" (which didn't work) or "revert". Clicked revert. Reopened document. Shortly the message came up again, "Document could not be auto-saved, has been changed by another application." Tried to "save anyway." Still says I don't have permission, even though Finder > Get Info shows document unlocked with me as holding "read & write" privileges.

Am I going to have to unlock every single document every single time I want to work with it??

Can someone explain what revert, duplicate and save a version mean? I hesitate to use them b/c I don't want a bunch of duplicate files on my computer.

And now, a file that I've been working with for a few days is telling me it "could not be reverted." What does that mean??

I am relatively new to Mac, I love it but I am frustrated because these changes just came out of the blue. Any help would be appreciated.

Thanks!!