Did you get any feedback regarding your issue with the plug-in?
I've started using WP 271 hosted by GoDadday and Plug-In 1.5.
Using either the Classic or the WP 1.6 themes, I have the same problem. When the page first loads, the slideshare frame flashes briefly but once the page is loaded the frame is blank. Right clicking on that region says 'movie not loaded'.
I've looked through other support forums but haven't found any solution yet.
There doesn't seem to be very active support responses for the plug-in.
I'd appreciate any information you may have received!