Columns Extension not playing nicely with DPS custom fields

Hi Bill, I wonder if you or any of the other readers have come across this?

I am using the Columns Extension plugin and need to add some custom fields.

My shortcode is:
[display-posts wrapper=”div” wrapper_class=”speaker-list” image_size=”thumbnail” columns=”6″ no_posts_message=”Sorry, no speakers defined”]

Columns Extensions works fine until I add the code and then I lose the columns.

I have cut the code right down to:
add_filter( ‘display_posts_shortcode_output’, ‘be_display_posts_custom_fields’, 10, 6 );
function be_display_posts_custom_fields( $output, $atts, $image, $title, $date, $excerpt ) {
}
i.e. do nothing, and still the Columns Extension plugin doesn’t like it. There is no indication in the html that columns are being set.

I have removed all other plugins.

Can you shed any light?
Thanks,
Phil.