Since server upgrade from 1.6.8 to 1.8.2, some items are up to date. Last returned value is before the update. Nothing esle has change except the server version.
This issue is not related to host agent version or active/passive mode.
What I have noticed, is that items with ID bigger than 77804 are not more updated since the upgrade. Items with ID smaller than 75836 are working well. Between these items ID I have templates.

Items who are not updated appears in server queue. It seems that the server see it has to request hosts for these items but it can not do that.
Nothing appears in Server or agent log.