This may be due to the roboform application not being fully Windows 7 compatible yet. One thing you could try is run the application as administrator, (right click run as...), Activate the application and set your passwords, then hopefully they will be retained.
This is caused by some older programs insisting in storing settings files in the program folder which under Windows 7, in not accessible to the normal user account maintained by the UAC.
Hopefully after setting the items running as a normal secure user will work as intended
Hope this helps