There is a bug in the Mac OS 10.4 and 10.5 whereby the entire system can freeze when certain events take place in USB communication.
This bug can be tickled by the combination of Logger Pro, a Go! Link, and a G5- or G4-based Mac. Apparently Intel Macs and earlier Macs are not affected, or at least we have not seen the problem on those machines.
The symptom is a total freeze of the computer, with only the mouse cursor moving. There is no recovery other than restarting the computer. If the default auto-backup is still enabled, a backup file that is most of the data collected so far may be available.
There are three possible workarounds:
1. Use an Intel-based Mac
2. Use a LabPro or LabQuest for long data collection on the G4 or G5 Macs.
3. Use Logger Pro version 3.5 or earlier or Logger Lite 1.3. Both use a different set of calls for USB communication, and will not trigger the bug in the OS.
There is no known timeframe as to when Apple will fix this problem; Apple has said it is not high priority for them.