Which version of TurboLink is this?
If you have the Windows version, be sure you are running v4.0.4 (it's got some additional synchronization "smarts" in it)
If you have v2.13, if it is recording, it only has room for about 7 minutes worth of data, so it stops recording (however, it should reconnect with no problems).
The other thing to check is your laptop power settings. Some of them have a "stand by" mode when on battery that shuts off the harddrive and the external ports after a configurable time. That might be what's doing it also ....