Yes I also meet this problem and it is solved as lothei said with disabling XHTML. This is not PHP addon related problem. It occurs on any other configuration when you paste from bad source or make incorrect things in 'Source' mode.
I have this problem too sometimes, it seems to happens because some html tags are not correctly opened or closed (for example u have a <font> and no </font>, ie and word usually make these sorts of errors) It seems to stop happening when i disable XHTML: <fckconfig.js> FCKConfig.EnableXHTML = false ; FCKConfig.EnableSourceXHTML = false ;
RE: Doubling content (BAD BUG!!!)
RE: Doubling content (BAD BUG!!!)
It seems to stop happening when i disable XHTML:
<fckconfig.js>
FCKConfig.EnableXHTML = false ;
FCKConfig.EnableSourceXHTML = false ;
RE: Doubling content (BAD BUG!!!)
Thank you guys, I owe you a beer!