Acrobat 9 Pro: tools don;t stay selected?

I do a lot of markup using the commenting tools when grading test papers. I primarily use three tools: highlight, oval, and rectangle, all of which are color coded as per my preferred settings.
 
I could have sworn that in previous versions of Acrobat you could select one tool (say the oval) and it would stay selected until you switched to another tool. Is this no longer the case? Or is there a user preference for this that I'm just not seeing?