Signature Textbox Failed

Something is wrong with your WYSIWYG Program for Signature since I am unable to delete any of my content after submitting it unless I go to the Administrator Control Panel and delete it that way,
I can not jump between Lines with my mouse or Arrows,
When I highlight a text by holding my mouse and scrolling across it I am still unable to delete it,
When I used the Bold Button I was unable to get out of it (It even showed it as off but still used the bold

It would be better for me to stay in the other Editor Mode then continue using your newer Editor Mode until you allow easier and better control for when you are using it.