No heavy border on default push button

[tremolux66]

I've created an AutoIt script with a single GUI that includes a set of push buttons, one of which is the default. I can get the default button to operate as desired, but it renders without the heavy black border described in the AutoIt help (GUI Control Styles appendix) and the user has no visual cue for the default. The button creation code:

$idSrchBtn = GUICtrlCreateButton("Search", 710, 120, 60, -1, $BS_DEFPUSHBUTTON)

With an accelerator associating {ENTER} and $idSrchButton, I get the desired behavior; removing the accelerator causes the button having the focus to be clicked on ENTER. (The colored border for the focus is the only [static] button highlighting.)

Is this a case of programmer error? A bug? If so, is there a workaround?