problem creating a user account Rated 2 out of 5 stars

there is a problem creating a user account because of this module, it sends an error message:
Could not be created profile. Probably the chosen folder isn't writable.
[Exception ... "Returned Component failure code: 0x80520015 (NS_ERROR_FILE_ACCESS_DENIED) [nsIToolkitProfileService.createProfile]" nsresult: "0x80520015 (NS_ERROR_FILE_ACCESS_DENIED)" location: "JS frame:: chrome: / / mozapps / content / profile / createProfileWizard.js:: OnFinish:: line 233 "data: no]

I do not understand why?

This review is for a previous version of the add-on (0.3.1).