debug.txt says =WebStatistics: Bad logfile line=

On our installation, the debug.txt contains two new lines per day, like this:

| 2010-08-30T03:45:02Z debug | WebStatistics: Bad logfile line resetpasswd&vbar;def345&vbar;Mozilla&vbar;10.0.120.154 |
| 2010-08-30T03:45:02Z debug | WebStatistics: Bad logfile line resetpasswd&vbar;abc123&vbar;Mozilla&vbar;10.0.121.91 |
| 2010-08-31T03:45:03Z debug | WebStatistics: Bad logfile line resetpasswd&vbar;def345&vbar;Mozilla&vbar;10.0.120.154 |
| 2010-08-31T03:45:03Z debug | WebStatistics: Bad logfile line resetpasswd&vbar;abc123&vbar;Mozilla&vbar;10.0.121.91 |

Some observations:

The error log is empty.
The crontab runs with the same user as the Apache.
We use crontab to execute the stats script once nightly. The ./statistics script is only listed once in crontab. The entry is exactly:
0 0 * * * (cd /opt/local/wiki/htdocs/bin; ./statistics >/dev/null 2>&1)
The string resetpasswd&vbar;... is very odd! The substrings abc123 and def345 are (obfuscated) Foswiki login names.
Foswiki performance is generally okay and I've not seen any problems causing or being caused by this issue.
I've googled and found a few other similar incidents, but nothing that seems directly related: 1, 2, 3

What's going on with our statistics? How do I get rid of these logfile lines?

I have the same problem with "sudo" log file entries. Apparently the statistics script chokes on unknown log entry types...

-- AndreasKeil - 06 Dec 2010

I've created an urgent task to resolve this in 1.1.5. Tasks.Item11545. In addition to the unknown event types, template webs also result in statistics errors being logged. Search engines finding the _Extensions template web on Foswiki.org is flooding our logs - every search hit logs an error with every statistic run.

-- GeorgeClark - 21 Feb 2012