I use Opera too and I get the same problem. When you submit, Opera seems to add a ^M to the end of each \n, so the problem actually gets worse and worse every time you preview (double the newlines every time). You can actually delete the extraneous ^Ms cos although you can't see them, they're on the end of every line, so if you go to the end of the line and get rid of any whitespace you shouldn't see this problem.