Incoming changes do not display correctly when a server sends a pull bundle

I have a large repository that is served over http with some pull bundles generated to reduce server load.

Say the server has sequentials changesets 1 to 10 and a pull bundle containing changesets 2-10. If I am on changeset 4 the server seems to send the pull bundle as when I query for changes in TortoiseHg displays this instead of the relevant changes:

• The "Found xx incoming changesets" bar displays correctly
• The graph displayed below however shows the entire contents of the bundle (in this case changesets 2-10)

I'm running TortoiseHg 6.6.3 on Windows.