Easy Nivo Slider & the_post_thumbnail

Hi there,

I use the following code to display thumbnails in a list of posts:

<?php if(get_option('thumbnail_size_w') > 100 && get_option('thumbnail_crop') == 1) {
    the_post_thumbnail(array(100,150));
}else{
    the_post_thumbnail('thumbnail');
}?>

Along with the functions.php code `<?php
if ( function_exists( ‘add_theme_support’ ) )
add_theme_support( ‘post-thumbnails’ );
?>`

I also want to use the Easy Nivo Slider plugin too, but when activated it is causing this error:

Warning: trim() expects parameter 1 to be string, array given in /home/wwwhydra/public_html/wp-content/plugins/easy-nivo-slider/3rd-party/filosofo-custom-image-sizes.php on line 31

If I remove the the_post_thumbnail from my code or deactivate the plugin, things get back to normal, so there is clearly a conflict between them.

Any ideas how I can get around this as I want to use both things.