I've tested this on a few wordpress sites running 2.5.1, 2.6.2 and 2.7 and all have the same problem.
I can view the slideshare player but the slideshow doesn't load - there is a continuous 'loading' icon in the middle of the player.
If I take the normal embed code (extracted from the div to just show the slideshow player and no links) the slideshow works fine.
If I look at the source html produced by the plugin compared with the pasted embed code I can see that there is no link to any document after this http://static.slideshare.net/swf/ssplayer2.swf?doc= in the embed code produced by the plugin.