FCKeditor adds some symbols

Hi everyone, I'm using FCKeditor that's built in MojoPortal (ASP.NET platform) and every time I add some markup to a text inside editor it adds some tags and symbols like <p> </p>... Each time I need to remove it myself from the source view. No problem I'll do it but what about a person who doesn't know anything about HTML?
There should be some solution for this problem, maybe in new versions of FCKeditor. If there are any workarounds I'd be glad to hear them .

Thanks

Giorgi