There is a known issue with Windows Vista and the sleep and hibernate modes.
Upon "awakening," the NET service (capture utility) is not running.
Apparently, Windows shuts this service down and does not keep a record in RAM.
When the computer is used again, this service must be manually restarted.
Solutions--
Do not utilize sleep or hibernate mode in Windows Vista.
Instead, either shut Windows down completely or
Only shut down the display/monitor instead of putting the system into "sleep" mode.
