TYPO3 Core

You're talking about the TYPO3_4-2 branch, don't you (since rev. 4667 and 4670 are only there)?
If tested it with TYPO3_4-2 rev. 4679 and Trunk rev. 4677 and could not confirm this issue.
Please test, if deleting the files in ./typo3temp/rtehtmlarea/ helps

I can't confirm this too.

After updating rtehtmlarea from SVN, you should delete all files from directory typo3temp/rtehtmlarea and clear the browser cache.

ciao Stanis. that worked!
i am sorry this happened to me some years ago... there should me a remind to empty typo3temp/rtehtmlarea !!!

As soon as the version of rtehtmlarea gets increased, the tempfiles in typo3conf/rtehtmlarea/ will be regenerated automatically. However, if you use SVN revisions the version does not change and thus cached JavaScript data remains...

I'm closing this issue since there is no change required in the TYPO3 Core.