You can tell whether a trigger is enabled or disabled at any point in time by ANDing the status field in the sysobjects with 2048. If True, the trigger is disabled otherwise it's enabled :
SELECT Name,
(status & 2048)
FROM sysobjects
WHERE type = 'TR'
I don't know a way of telling historically WHEN the change was made....I guess you could put a trigger on the SYSOBJECTS table itself that writes an entry to an audit table when the STATUS column changes.
Just an idea though.
Chris Lawton
Chris.Lawton@GoldMine.com