Why does Mellel saves files I do not want saved?

Why does Mellel saves files I do not want saved? I have written a document and wanted to save part of it, so I've deleted most of the document and then quit. To my horror, I've discovered that Mellel saved the truncated file anyway. Why? 

Mellel's saving behaviour is set by your Auto-Save setting. For most users, the option set by default is using the system standard (with Lion or better). The system standard version allows browsing through past versions of a document, so you can recall a previous version of the document.

If you have the Auto-Save set differently, you can also rely on the backup copies of files Mellel keeps (you can access those through the Preferences > Open & Save).

In your case, you may have Mellel set to automatically save files every five minutes. To change that, do the following: 

  1. Choose Mellel (menu) > Preferences... and navigate to the Open & Save tab. 
  2. With Automatic Save, choose Off (no automatic saving), System Standard, or Save Every XX minutes. If you wish Mellel to save files automatically rarely, change the setup to Every 120 minutes or simply turn auto-save off. 

If you wish to retain auto-saving, but want to avoid mishaps, remember that Mellel can undo beyond a save, so you can simply undo any changes you've made, and then save the file intact.