Fleck has been updated for IE. It was notified by Fleck, today on their blog. They have been working on it for long since the service was launched initially for Firefox.
Here goes their explanation for the problem they faced with IE integration as compared to that with Firefox –
In Firefox we get a clear error when something goes wrong with a hint of where the error might be. Explorer just gives up, crashes or just sits there doing nothing.
Now you can annotate pages in IE :M).