Not sure if this is a bug
per se, but it's behavior I don't previously remember seeing:
When you do a search (searching all HTML files), cycling through results by hitting "Return/Enter", the cursor jumps from the search box to the html code when you cycle to a new html file. Hitting return again consequently deletes the selected string (in the html code) and inserts a carriage return.
I also ran into Zeypxi's conundrum, except it's far broader than his example implies. It's not limited to inserting images.
Any coding error that prompts a message on switch from CV to BV locks you out if you try to fix the problem manually, requiring a complete restart and loss of any unsaved work. If Sigil can fix it automatically, it does, but repeats a second error message that says:
Code:
The operation you requested cannot be performed because (filename) is not a well-formed XML document.
An error was found on line N/A, column N/A:.
etc...
which you can escape by selecting Fix Automatically a second time (although as best as I can tell, it's not actually executing any sort of adjustment in the code on this second click). If Sigil can't fix the initial problem automatically, you have to do a hard restart (from the Task Manager) as already noted.