I know about this thread: tv debug growing in ZA Pro 9.1.008, and other posts about the debug setting in ZA. This is just feedback.
I did a clean install of ZA Free; ver. 9.1.007.002 some days ago (used the ZA Free before that, as well).
That is, clean install "the old way"; remove check mark for Load ZoneAlarm at start, restart the PC, add a "/clean" switch to the uninstall software and let it restart to finish the uninstall, did some small cleaning and then installed the latest free version and everything is working all OK.
I did however notice that the tvDebug.log file was whooping 2.5 GB in size and changing. The debug level (never touched that one in earlier installations and no matter that, it was a clean install) is set to “Default”.
Since this a "simple" ZA Free; no other problems are seen; it has not been a problem before; I assume this is not some conflict with other software.
As you have mentioned, I can only assume that somehow both the "High" and "Default" debug level settings are pointing to a High setting in the code, and that the only setting that makes a difference is "Off", at least at the moment and in the latest release (and when doing a clean install).
Just to report that the problem is seen in ZA Free, the latest version 9.1, in a clean installation.