I'm having the exact same issue as here:
The only difference in mine is that the line number is different - instead of line 1357 mine is line 1451. I tried to replicate the solution that worked for blowbackk (http://wordpress.org/support/topic/plugin-digg-digg-new-plugin-doesnt-work?replies=5) but I can't figure out exactly what he did with "true". I'm assuming he meant that he changed "false" to "true" in a couple of the lines, but when I tried it I just end up chasing the error through the file - I end up with a different line number, but the same error.
I'd really like to get this to work since it's ideal for what I need. Can anyone help?