Ok, I have tried versions 3.0.8, then 3.0.10, and then went back and tried 3.0.6. I uninstalled the previous version each time. On the Force Quit Reasons, it all seems the same each time to me, but it is a very long report and I know basically nothing about the information in the Reasons report.
I still start Vbox and it hangs with the spinning cursor each time. I am copying in the beginning section only of the Reasons report in the hope someone else may be able to see something to help me track down the problem. In this report, about the only differences I can see in the different times I have looked at it with the different versions were the leading number in the "user stack part," which in this pasted report was "9".
I will take any inputs, please.
Date/Time: 2009-10-31 01:57:34 -0700
OS Version: 10.6.1 (Build 10A2047)
Report Version: 6
Version: 3.0.6 (3.0.6)
Parent: launchd 
Duration: 2.99s (sampling started after 2 seconds)
Steps: 9 (100ms sampling interval)
Process: VirtualBox 
Process: AirPort Base Station Agent 
Path: /System/Library/CoreServices/AirPort Base Station Agent.app/Contents/MacOS/AirPort Base Station Agent
Thread 95c57a8 DispatchQueue 1
9 ??? (in AirPort Base Station Agent + 5344) [0x1000014e0]
9 ??? (in AirPort Base Station Agent + 70666) [0x10001140a]
9 CFRunLoopRun + 70 (in CoreFoundation) [0x7fff804a4dc6]
9 CFRunLoopRunSpecific + 575 (in CoreFoundation) [0x7fff804a503f]
9 __CFRunLoopRun + 2002 (in CoreFoundation) [0x7fff804a5ce2]
9 mach_msg_trap + 10 (in libSystem.B.dylib) [0x7fff815a8d5a]
(FROM HERE THERE ARE MANY SOMEWHAT REPETITIVE SECTIONS THAT LOOK LIKE THIS AND QUITE A LARGE REPORT)