Dear denizen2 -
Clicking the OK button once should also work just fine, as it did for me when making those screenshots for instance.
Here is more specific info about when the double-click is required: When any indicator
parameter value is changed, say by entering a new value, then if I click the OK button, nothing happens until I click it a 2nd time.
Here's why: If you watch the mouse 'black-focus' mark all during this two-step procedure, you will notice that the first click (anywhere outside of the parameter value field) will remove the black-focus mark that covers the parameter value just changed. I presume that this is supposed to mean that the value has been 'entered' and 'accepted'. But that is really un-necessary. As it is now, it is only until focus has been removed from the original field does the OK button even become 'active' or 'listening'. Thus requiring the double-click

.
If I had just changed a 'radio-button' type selection, then this problem never occurs, e.g., when you just changed the scale mode between 'linear' and 'semi-log'. That was because there was no 'active focus' issue involved.
I would suggest that the 'focus' (Windows programming) behavior-logic should be changed so that if the OK button is clicked, then it means that any changed parameters values are automatically accepted (i.e., OK). It would sure be more consistent behavior than trying to remember if the last property change was a radio button, or was it just a parameter value that was changed?

OK? What do you think?