After extensive trials, Outlook 7 loses names in Blocked Sender list when it is closed and/or computer is shut down with Outlook open. This applies only to Windows 7.
As long as Outlook remains open, names are retained in memory.

Same computer booted to XP does not lose names when Outlook is shut down or computer is shut down. A second computer with XP gives same results, as does a third computer with Vista. It seems to me that the problem is some kind compatibility issue between Outlook 7 and Windows 7. Anyone who solves this will make a lot of people happy.

Any ideas?