doesn't work on Win7, Firefox 4 Rated 4 out of 5 stars

installed latest version (1.0.5.07). the calendar doesn't appear in the bottom bar and going to options and clicking OK generates an Java Script error: "TypeError: opener.opener is null"
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This review is for a previous version of the add-on (1.0.5.06.1-signed.1-signed.1-signed).