In case you are wondering the log files in question are hidden in the /cfusionmx7/runtime/lib/wsconfig/ directory. You will see numbered directories in there - possibly one for each site depending on your configuration. inside the numbered directory will be a sub-directory called "LogFiles" and inside of the logfiles directory is a set of, you guessed it, log files. These files log operations associated with the wildcard ISAPI filter. Elliot’s log files where growing quite large on a daily basis.
Now I had not seen this problem before. I have never found any useful information in these logs so I largely ignore them. On my server the logs roll over each day and there is a just a few lines in each - about 200 to 300 bytes per log. That got me curious. What conditions would cause these logs to grow all the time. It turns out there is an INI file in each numbered directory. It's named (on my server) jrun_iis6_wildcard.ini. There is also, on another server of ours (win2k with IIS6) a jrun.ini file in that directory.
Looking in this file I saw immediately that the top line is verbose=false. On the IIS6 server there is also an ini file titled jrun_iis6.ini that is located in the /wsconfig/ folder. It also contains this setting. On our (iis6) server the verbose setting was "true" for this "root" ini file (the one in /wsconfig/) and "false" for all the sub-ini files (the ones in each of the number directories). I asked Elliot to check his setting and he found that his sub directory ini files had verbose set to true. Changing it to false and restarting his CF Server seems to have fixed his problem.