I use Chrome and Windows 8.
I see two returns in your post. It doesn't happen ally the time for me. Just enough times to be annoying.
If you are a comp-geek like me....it is more than annoying....mainly because goofy shxt happens almost ALWAYS at the most inopportune time.
Sort of like the 'stress sensor' on the photo-copier that KNOWS when you absolutely... right now ...have to copy something....and the copier 'blows up'.