Any solution to this problem?

Scenario:
Windows 7 SP1 64bit
Firefox 3.6.22
Simple Mail 2.80.1

The Simple Mail update above (from 2.80) removed existing folders, messages and settings from the user's set up, and displayed the default 'Welcome to simple Mail' message, suggesting a newly installed extension rather than an update. The 'Data Directory' path had been set to 'C:\Users\username', a location that contains a simplemail.sqlite file.
On resetting the 'Data Directory' path to the Simple Mail Directory in AppData\Roaming\Mozilla etc., all folders, messages and settings were restored, and messages sent to the recipient account since the 2.80 update were downloaded from the server. However, no new messages sent to the user's mail account since the 2.80.1 update have been downloaded or, if they have been, are not accessible via the Simple Mail interface in its present configuration.