Yes, I have also had somewhat similar problems. I'm running TestComplete 9.31.
In my case, I have Windows Scheduler launch TestExecute and start the test run on a remote test machine several times per week. It starts at 10:30 pm and finishes about 7 am the following morning. Most days it works fine, but on Saturday morning it stops somewhere between 2 am and 2:30 am. This has been happening for several weeks at least.
TestComplete logs show that the last test item completed successfully, no errors are shown on screen or in logs, and I haven't found any unusual entries in Windows (7) system event logs, or even any log entries that are common to the different failures.
No Windows Updates or defrag is going on in the test computer at the time.
It's like the test run just ... stops.
I don't know of any other logs to check, and because of the long running and auto scheduled nature of the process it would be difficult to use Report Generator.
I'm pretty much down to 'don't use that machine on that day' as a resolution :/
