Photoshop Elements :: 11 / Saved Version Treated As A New File

When I edit a picture and save the result (using either "save" or "save as" and making sure there are ticks in "Save in Elements Organiser" and "Save in version set with original"), the edited copy is often (perhaps 3 times out of 4) treated not as a new version but as a new file. When I close the edit, I am told that there is a new file in a watched folder. When I accept this, I am offered any tags which were applied to the original (which works a bit) but then have to find my way to the edited file and the original, and manually make them into a set. It adds a couple of minutes to each edit. I am using Photoshop 11 on a Windows 8 laptop with a 1000GB hard disc (with about 100GB free). My catalog is quite big- about 70,000 items. I am a long-time Elements user (since the original?). This problem is fairly new (ie months not years)- certainly since I moved to V11. This is independent of the format of the original (in my case, RAW or jpeg) or the edited file (in my case usually jpeg).