This issue was brought to my attention when
This is likely what happened:
The user's question was answered by
http://www.livejournal.com/support/act.bml?close;28958;authcode;104919
they entered:
http://www.livejournal.com/support/act.bml?close;28958;authcode;10491
If you look at support request #2802,
Since the answer was made before the request, LJ::Support::calc_points returned a negative point value. Since the points column in the supportpoints table is an unsigned tiny integer, the negative value was stored at 0 in the database.
I've made a patch which fixes act.bml so it'll only let you credit an answer that was in response to the request you're closing. Also, only answers can be credited. The patch is available from http://www.teencity.org/act.bml.diff.