I changed an issue in my tracker and got templating error with "exceptions.ValueError: second must be in 0..59".

Roundup had made an invalid time stamp to activity field:
# roundup-admin -i var/roundup/tracker get activity issue63
2006-12-16.16:15:60

That time stamp prevented web interface to show the issue . I couldn't modify the issue either (from command line...).

The cause of such time stamp might be some kind of rounding error in roundup.date.Date class when it generates current time. I don't know how to repeat that bug.

More about this in roundup-users mailing list:
http://thread.gmane.org/gmane.comp.bug-tracking.roundup.user/7611/focus=7611

The version of roundup was 1.2.1 (python 2.4.4) (Debian testing) and the backend was anydb.