Make sure you are selecting the text from the "BBCode" box...do you know how to cut and paste? After highlighting the text you want to copy, click your right mouse button to open the pop-up menu and select "copy", then go to the Edit Signature screen (I personally use the Quick Links menu), position your cursor in the box and righ-click again and select paste. You can see if it pasted correctly by clicking "Preview Signature" - your ticker should show up in the space above the text box.
Good luck, let me know if you've tried all this and are still having problems...