great extension but errors Rated 4 out of 5 stars

I have many of these error in my error console:

Error: [Exception... "'JavaScript component does not have a method named: "getRowProperties"' when calling method: [nsIMsgCustomColumnHandler::getRowProperties]" nsresult: "0x80570030 (NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED)" location: "JS frame :: chrome://showaddress/content/showaddress.js :: anonymous :: line 287" data: no]
Source File: chrome://showaddress/content/showaddress.js
Line: 287

This review is for a previous version of the add-on (0.0.4).