Sync job aborting

Error details: Synchronization steps aborted. Details: An error occured while import from 'OU=xxxx'
Unknown error (0x80041070)]

any ideas how to dig into this one, this job runs hourly for our new users and termed

it eventually clears up, but dont know where to look to investigate 

nothing has changed in our process. we have four steps in this sync job, and it keeps failing at step 3, but there are no other insights