I think you mean the "Thickbox and lytebox" hack from my homepage. If so, I have updated it. In displayimage.php you can now set thickbox/lytebox/normal to default.
There is also a new config value "alwaysauto" - I do not know if that makes sense, but I had the idea and could not resist
You need to edit displayimages.php.
Open the file in an editor, at line 77 you find
$CONFIG['lb_display'] = 'thickbox'; // thickbox,lytebox,normal
replace 'thickbox' with 'lytebox'.
All behind // is a comment and need not to be changed.
The other settings are on/off settings, for example $CONFIG['lytebox'] = 1;
if you replace it with $CONFIG['lytebox'] = 0; the option 'lytebox' will not be shown in the dropdown.
At line 603 you find $info['Effekt'] = 'Wie soll das Bild dargestellt werden: '.lb_change();
You can change the text to something you like, for example $info['Effect'] = 'How to show the image: '.lb_change();