also sprach andrew <andrew@2sheds.de> [2005.05.12.1750 +0200]:
 
I have been looking for the last 2 days, and still haven't worked out 
why logrotate on a standard sarge installation rotates all files in 
/var/log. I have created a new log file in syslog that outputs to 
/var/log/local1.log. As I am using swatch to watch this file, I do not 
want it rotataed, but somehow logrotate still manages to rotate it. How 
do I turn off this feature in logrotate for this one file?!
   
It's not logrotate but /etc/cron.*/sysklogd which rotates the file.
Unfortunately I know of no way to disable it.
sysklog does its own rotation of all files referenced from
/etc/syslog.conf, and Debian is not using logrotate for those
because only the current solution allows the system to automatically
rotate any user-specified log files. This acclaimed feature is what
is biting you.