Problem with Fill and Sign Tools "Add Checkmark"

I am using Adobe Acrobat XI Standard.  When I click on the "Add Checkmark" icon under Fill & Sign Tools and I click on the exact spot I want the checkmark to appear the cursor either bumps it up to a line above the spot or a line below the spot.  It won't checkmark the exact location I place the cursor.  I had this problem happen once before and I called Adobe technical support.  After practically begging them for help because they told me they didn't support my version of Adobe for support they finally helped me.  He walked me through quite a process to fix the problem.  I asked if I could get an email with the instructions in case it happened again and he said he couldn't do that.  I would have to go to one of the forums for help if it happened again.  Here I am.  Can anyone help me?