impediment on work item not recorded automatically

[adamfoneil]

I just noticed a comment marked as impediment, but it didn't reflect on the work item.
Manually fixed it:

SELECT * FROM [WorkItem] WHERE [Number]=2558
SELECT * FROM [Comment] WHERE [ObjectId]=4110
UPDATE [WorkItem] SET [HasImpediment]=1 WHERE [Id]=4110

[adamfoneil]

this happens when you update a comment as an impediment -- the update doesn't reflect on the work item as it should