Just about every week, I'll be working in a custom control, adding features, changing items for readability or adding js to buttons - whatever... when the next time I check in my browser, my changes aren't there.    Hmm.. maybe I didn't save it - yep, it's saved.  Ok, now what - oh, look, I HAVE 81 ERRORS ON THE PAGE.  What gives?  Well, lo and behold Designer has somehow corrupted my page with multiple duplicate tags of virtually my whole page.  So, now I have to spend the next hour going through my source LINE BY LINE to delete out the duplicate code.

 

As I said, this happens quite frequently - like once a week - and sometimes more than once a day.  I thought maybe it was because I copy-and-paste code from one page to another, and thought maybe that was my problem.  But, I don't think that's it - as it has just happened again.

 

Has anyone else had this happen to them? - is their a known cause? - or, could it just be me and my setup?