As actually occurring to other plugins such as NextGen gallery,
[slideshow] shortcode conflicts with Jetpack by WordPress.com.
So please wait a couple of days for an alternative additional
[comboslideshow] shortcode in the upcoming 1.5 version.
In the meantime you could also:
* disable Shortcode embeds in Jetpack
* edit the Combo Slideshow .php files and replace the shortcode name
* edit Jetpack .php module for shortcodes and disable adding the shortcode named "slideshow"
Other known issues are:
* the "Gallery" label in the auto single post/page actually points to the Blog (make sure you have thumbnails set in each post!). Another button will be added.
* the CSS rule for the "slider-wrapper" div should be set to "position: relative"