I'm having an issue with the service failing as well. I originally thought it was something else I had installed on the box as it was restarting itself as well, so I just wanted to start clean as it was running the beta version previously. I reinstalled the OS (Windows Server 2008 R2) and SQL (SQL 2008 Enterprise x64). The same symptoms happened again, so I rebuild the box again on 5/5/2010 with Server 2008 SP2 x64 and it's still happening. I set the service to restart itself, but it will only do that so many times in a period of time. Here are some the error messages in the application event log. There are more if you need them, but these are the three that show the differing faulting modules.
5/8/2010 7:21:50 PM
Faulting application Lansweeperservice.exe, version 4.0.0.24, time stamp 0x4bd85ed0, faulting module ntdll.dll, version 6.0.6002.18005, time stamp 0x49e0421d, exception code 0xc0000374, fault offset 0x00000000000aef37, process id 0x2a04, application start time 0x01caeefd809b6120.
5/8/2010 7:21:49 PM
Faulting application Lansweeperservice.exe, version 4.0.0.24, time stamp 0x4bd85ed0, faulting module mscorwks.dll, version 2.0.50727.4200, time stamp 0x4a9ee32d, exception code 0xc0000005, fault offset 0x0000000000292007, process id 0x%9, application start time 0x%10.
5/5/2010 3:44:28 PM
Faulting application FWASU.exe, version 2.0.3.0, time stamp 0x4b86ddf3, faulting module KERNEL32.dll, version 6.0.6002.18005, time stamp 0x49e041d1, exception code 0xe0434f4d, fault offset 0x00000000000176fd, process id 0x%9, application start time 0x%10.
Should I not be running x64? It's running on a standalone box, not in VM and I've never had IP Scanning turned on, just Active Scanning. It seemed to work well in beta just fine. Is there anything else I can provide to help figure this out?