preseeded partition attempts to proceed too fast

With a fully preseeded configuration, including automated partition via a custom recipe, the installer attempts to proceed through the partitioning too fast resulting in transient errors being presented to the user such as the following:

====8<========================================================>8=====

Could not stat device /dev/mapper/vg0-home - No such file or directory.

ERROR!!!
    Retry
    Cancel

 <Go Back>

====8<========================================================>8=====

The specific device it errors on tends to vary. Sometimes it errors on mutliples, sometimes only one. In every case, simply selecting Retry works.

Perhaps the partitioning process should attempt to sync out device changes and/or wait for changes made to settle in.

I've been able to reproduce this issue quite reliably using a virtual machine with a 40G drive and the attached seed file. The installs have been a seeded oem-config.