TYPO3 Core

Sorry to say, - you are wrong. HTMLArea is doing it correct. Enter (hard linebreak) wraps the paragraph with <p> .... </p> who is correct. Shift-Enter (soft linebreak), end the line with <br />, who is also correct.

<br /> should never be standard behavior for Enter, because Enter (hard linebreak) are defined as end of paragraph and not end of line. Every Word-Processor made has this behavior, and it's also correct HTML-coding.

Have no problem in any of mine 4.0 installs (either HTMLArea are configured or not), with using <p> and <br /> like it should. I'm also using FF as browser.

My conclusion. Not a bug.

IE produces a p tag when you hit enter. Making IE enter br instead of p is not a planned feature. Shift-enter will produce a br tag.

Mozilla/Firefox produces a br tag when you hit enter. However, htmlArea RTE makes this configurable so that you can produce a p tag when you hit enter. This is the prefered behavior.

This default behavior will not be changed unless you can get consensus on such change from the subscribers of this list:
news://news.netfielders.de/typo3.projects.rte

Please: "Current version of the RTE" is not very informative.