k. So here is the deal...
The help buttons must be vertically aligned top or tall controls look awful. But, the top padding of its parent cell is set such that the help will be middle aligned with a single line of text when the text is allowed to be its recommended height. This make the help button look right next to all the checkboxes and radio button lists in the config form as well as tall controls.
For lines where there is a text input or button, the text line is taller than lines where there isn't a form element. In those cases, the button does not look vertically aligned middle and thus seems slightly off.
I can set the minimum line height to match the height of the form input buttons, but that will make the long form longer, so I am reluctant to do it. But, if there are continued complaints, I will try that next.
I just don't have enough data, short of doing a bunch of JS hacking, to know the exact right rule to apply to that button.