hobbit/xymon apt checking says "Packages not installed from apt repositories", from upgraded Ubuntu

We upgraded version 10.04 to 10.10 Ubuntu. Hobbit is giving us a warning on the Monitoring page saying: "Packages not installed from apt repositories (1): linux-image-2.6.32-24-server (2.6.32-24.43)" even though a newer version is installed: uname -a: " 2.6.35-22-server #35-Ubuntu SMP Sat Oct 16 22:02:33 UTC 2010 x86_64 GNU/Linux"

how can we clear this? The sources.list doesn't have any repo's from Lucid . where does hobbit get this information from and how can we clear this?

tia!