Hi Grzegorz,
I can not reproduce unnecessary <br/> tags, but I have experienced similar things earlier in case of normal posts in WordPress. Yes, we suppose this might have been caused by the standard wysiwyg editor of WordPress.
The unnecessary <br/> tag is not inserted directly by our plugin.
Maybe we can make an option to turn off using of wysiwyg editor. Would you like this?
One more idea: You can try to add these lines to your functions.php file in your active theme’s directory to switch off automatic handling of paragraphs and line breaks in WP wysiwyg editor:
remove_filter( 'the_content', 'wpautop' );
remove_filter( 'the_excerpt', 'wpautop' );
If you still have any question, or we can do anything about this topic do not hesitate to contact us.
Regards,
Peter Rath
WebshopLogic