Gradually over a 24 hour period, the LansweeperService.exe climbs to 90-100% CPU usage and the website stops responding, and I can't open Lansweeper Configuration utility either. I just moved the server and database from a physical machine to a ESX virtual machine, and I made a couple changes in the Lansweeper options:
Changed 'set computers to non-active if not found in AD' to 'remove computers not found in AD' and 'set computers to non-active if not seen in last 14 days' to 'permanently delete computers not seen in last 60 days'.
When I reboot or restart the service, it works properly again for another 12-24 hours or so. I am using the latest version on Server 2008 R2 with SQL Express 2008 R2.