in the webassist\caching\CachedResiz e_Image.php file, change line 164:
if (!$this.resize_smaller && $this->width < $this->new_width && $this->height < $this->new_height) {
to:
if (!$this->resize_smaller && $this->width < $this->new_width && $this->height < $this->new_height) {