The screenshot won't help because there won't be anything there. As I said, when diggdigg plugin is activated, widgetkit slideshow widget just disappears from page html code. Here's my environment information for you to help with repro:
Theme (free): http://www.semiologic.com/software/sem-reloaded/
Activated plugins: Akismet, AmazonSimpleAdmin, Category Posts in Custom Menu, Fast Secure Contact Form, Google Analytics for WordPress, SEO SearchTerms Tagging 2, Simple URLs, W3 Total Cache, Widgetkit, WordPress SEO.
Repro: In widgetkit create a simple slideshow and add the shortcode to the home page. Without diggdigg the slideshow is visible and is working. With diggdigg, there's no slideshow code in the html.
I understand that there's possibility that one of these plugins participates in the conflict, but without diggdigg everything works just fine, so diggdigg must have triggered something which causes widgetkit to stop working.