Activity Stream items group unrelated commits

In the activity stream (e.g. fisheye dashboard page) activity stream items are grouped by changeset id and timestamp only. So if same changeset is found in different repositories it will be shown only once.
This behaviour seems acceptable for DVCS where hashes are meant to be unique. Having same DVCS repository indexed in few different fisheye repositories user currently see this item once only.
But this becomes problematic for svn for example where commit numbers are generated sequentially. Two unrelated commits made in two repositories with the same number and same timestamp would be grouped together. This is rather unlikely to happen with developers committing changes, but more likely with svnadmin dump/load activities where svndumpfilter was used to modify the history