[TYPO3-RTE] RTE deletes tags while saving

[Bjoern Kraus]

Hello!

The RTE seems to have a strange behavior: If I insert a hr-Tag (line) 
and click on save, the page is reloaded and everything is fine. If I 
click save again, the page is reloaded but this time without the hr-Tag 
(in FE you can't see the hr). I don't understand why this happens...

Here my page TSConfig (TYPO3 3.8.1 with css styled content):
---
RTE.default {
     hideButtons = left,center,right,table,image
     proc.allowTags = h1, h2, h3, div, p, br, span, ul, ol, li, 
blockquote, strong, em, b, i, u, sub, sup, strike, a, nobr, hr, cite, 
abbr, acronym
     proc.dontConvBRtoParagraph = 1
}
RTE.config.tt_content.bodytext.showButtons = cut,copy,line
---

Can someone help me out here?

Regards
Bjoern Kraus