[Plugin: Socialize This] Update of existing post throws fatal error

A scheduled post of mine was published this morning. I noticed that I’d made a typo in the post excerpt (left out the ampersand before mdash;). I corrected that and hit “update,” and got the following:

Fatal error: Call to a member function shorten() on a non-object in …/wp-content/plugins/socialize-this/inc/socialize-this-php5-enviroment.php on line 1148

I hit the back button and was brought back to the edit post screen in wp-admin. I tried pasting the “—” at the proper place instead of the HTML entity, but when I hit update I got the same error. I’ve reverted to the published version of the post for now, and all is well (other than the typo), i.e., my blog isn’t broken or anything.

Any thoughts/help will be greatly appreciated. I love the plugin, and how it’s allowed me to use my own custom icons – thanks for the work you’ve done on it, Mike.

http://wordpress.org/extend/plugins/socialize-this/