[Plugin: Lazyest Gallery] warning message on .png files

Just updated WP to 3.3.1 and LG 1.1.5 to 1.1.6 on my localhost WAMP server, testing before I update the remote site. When I added a transparent .png to an existing gallery I received the warning below. I didn’t see anything about .png files in the FAQ. Are .pngs a known problem, or is this warning caused by something else? I noticed on the generated gallery page .png transparency was lost on the ‘slide’, but seems to be retained on the thumb.

( ! ) Warning: imagetruecolortopalette() expects parameter 1 to be resource, null given in path\to\wp-content\plugins\lazyest-gallery\inc\image.php on line 360
Call Stack
# Time Memory Function Location
1 0.0068 1071104 {main}( ) ..\admin-ajax.php:0
2 0.3959 28837288 do_action( ) ..\admin-ajax.php:1587
3 0.3960 28838240 call_user_func_array ( ) ..\plugin.php:405
4 0.3960 28838256 lg_refresh_folder( ) ..\plugin.php:0
5 0.4109 28851344 LazyestImageTable->display( ) ..\ajax.php:676
6 0.4109 28851344 LazyestTable->display( ) ..\tables.php:401
7 0.4133 28851592 LazyestTable->group( ) ..\tables.php:52
8 0.4696 28853216 LazyestTable->row( ) ..\tables.php:76
9 0.4717 28854192 LazyestTable->cell( ) ..\tables.php:97
10 0.4717 28854192 LazyestImageTable->body_cell( ) ..\tables.php:118
11 0.4739 28855712 LazyestThumb->src( ) ..\tables.php:491
12 0.4741 28855856 LazyestThumb->cache( ) ..\image.php:627
13 0.4743 28855976 LazyestImage->newsize( ) ..\image.php:663
14 0.4743 28856024 LazyestImage->crop( ) ..\image.php:274
15 0.4801 29339888 imagetruecolortopalette ( ) ..\image.php:360

http://wordpress.org/extend/plugins/lazyest-gallery/