builds removed in multi-configuration job

[Douglas Moore]

One of our multi-configure jobs several of "keep forever builds"  are gone. The top level job shows the history but  both of the configurations are missing the actual builds.

ex. top level 3.0-release has history for builds 4,5 - 46 but the configuration jobs history  only as builds 5,46,48,49.

The job configuration should retain 10 builds. 

Its possible the builds were manually removed from disk but since for the configuration jobs build 5 was saved and all builds removed after until 46.

I wonder if jenkins might have done something strange.