Image lib - Problems watermarking orig and creating thumb copy

Code:
// main (original)

$main_image['source_image'] = './uploads/myimage.jpg';

$main_image['image_library'] = 'GD2';

$main_image['wm_text'] = 'newsXpress';

$main_image['wm_type'] = 'text';

$main_image['wm_font_path'] = BASEPATH.'fonts/arial.ttf';

$main_image['wm_font_size'] = '9';

$main_image['wm_font_color'] = 'CC2228';

$main_image['wm_opacity'] = 100;

$main_image['wm_vrt_alignment'] = 'bottom';

$main_image['wm_hor_alignment'] = 'right';

$main_image['wm_vrt_offset'] = 2;

$main_image['wm_padding'] = '2';

$this->image_lib->initialize($main_image);

$this->image_lib->watermark();



// thumbnail

$thumb_image['source_image'] = './uploads/myimage.jpg';

$thumb_image['image_library'] = 'GD2';

$thumb_image['create_thumb'] = TRUE; // assume this will create a thumb copy of orig???

$thumb_image['width'] = 92;

$thumb_size['height'] = 124;

$this->image_lib->initialize($thumb_image);

$this->image_lib->resize();