Forcing line breaks

Someone may have a better idea — I know some folks use the HTML tab and never revert to the Visual tab which causes the problem you refer to, as well as many others — but I use the extremely secure Shortcode Exec PHP plug-in, and use it to write my own php to insert HTML that won’t get touched in the Visual tab.

For example:

$space = '&' . 'nbsp;';
return " $space$space$";

is my shortcode for [dollar], which ensures three blanks before each dollar sign, used for restaurant menus.

As you can see from the need to separate the ampersand from the nbsp, the plug-in is not without its challenges, too, but it does work very well for me.

In your situation, you could use it to insert <p>, </p> and br /> for line breaks.