> WeepingLiberty, did you click the edit button, or did you use backspace (or equivalent) to go back?
> 
> That system with helpful errors looks wonderful...
> hmm... just got an idea... would it be possible to program it to so that uncooperative BBcodes (i.e. ones not written correctly) are marked out somehow? Say a shiny red (or some other color)? (in the submitted/previewed post?

Yes, I clicked the edit button on a posted response, made my changes and then clicked the save button. I then remembered that I forgot something so I clicked the edit button again, only to have the previous edit disappear on me when I did so. I originally thought that it might just have been that I clicked it without refreshing the page or leaving and coming back... However a little bit ago I returned just to test it... Every time I hit the edit button on a post I've already edited, my changes from before are erased. I have no idea why.