Mac LG VL600 lock up

[nestorph]

I recently upgraded to the LG VL600 and have encountered a problem that I used to experience back when I had the Verizon EVDO card.  If I am connected to the network via the broadband card and close my laptop without disconnecting, upon reopening the laptop, VZAccess Manager becomes dysfunctional.  It cannot detect the LG card anymore despite the card flashing blue indicating that it has a valid network connection.  There is no obvious process to force quit so I find that I have to reboot the MacBook Pro to be able to use the service again.  Quite annoying.  I know that the correct way to exit is to disconnect properly, but sometimes circumstances don't allow the time (e.g., your train stop suddenly appears and you have to jump off quickly!!).  Does anyone know of way around the problem without requiring a reboot?