I had a repeated item. I deleted it and search items for the module; then I did a re-index and everything looks good now.

It looks like this is a problem shared between the framework and the announcement module. I found this code in SearchDataStore.vb (part of the framework)

If searchItem.PubDate < objModule.LastModifiedOnDate Then
searchItem.PubDate = objModule.LastModifiedOnDate
End If
If searchItem.PubDate < objTab.LastModifiedOnDate Then
searchItem.PubDate = objTab.LastModifiedOnDate
End If

What this looks like to me ( although I am no vb coder and don't really know the code ), is that the search item's date is set to the later of the date that the module or the tab ( whatever that is ) was last modified. This will presumably be the date that you last entered added a news item.

I'm not sure why this is done; presumably for another component that needs it.

This looks like it makes the syndication for the announcement module unusable. Am I missing something? If so, can anyone suggest an alternative?

Indeed the PubDate shown in the RSS feed is determined by the logic shown above in SearchDataStore.vb. This means the PubDate will be the maximum date of Announcement-Item-PubDate, Announcement-Module-LastChangedOnDate and Tab-Where-The-Announcement-Module-Resides-On-LastChangedOnDate.

So if you change either the module or the tab (page) after the PubDate of your Announcement-Items, all your Announcement-Items will get the same PubDate of the last change of the module or tab.

  My workaround for this was to manually set the LastChangedOnDate for my announcement modules to an older date then my Announcement-Items PubDates. Therefore I updated the column   LastChangedOnDate in the tables Modules, TabModules and Tabs  for all rows with my announcement module ID's. Then I restarted my portal (to get clean caches), after then I cleared the SearchItem* tables and started a reindex.

After applying this workaround the RSS PubDates where in fact the PubDates of the Announcement-Items and stayed stable on further indexer runs.

Hope is of help to anybody.

Best regards,
Theo