Problem with flashscan datalogger

I've been experiencing this issue for a long time and finally decided to seek help.
After it's programmed and ready to scan I hit the green button, it lights and then shuts off.
Sporadically I can get it to log something and then if I disconnect the unit from the car and try and log again the green light will shut off again and it won't log data.
Once the logger is disconnected from the car or cable, it doesn't want to record.
Any guesses as to why the green light won't stay on?

Robz,

This is with FlashScan V1, right...?

In the programming window, set it up for 1 log file only (the log time should show something like 23 minutes).

Post a pic of that screen.

Joe