Delta queue entry not available

Hi Experts,

This is really vierd to me but all of a sudden we dont see an entry for one of the item level datasources in RSA7. the header and scheduline etc all are fine and the regular load went thru as well for others. RSA3 does show records for the same.

What are the possible reasons to lose an entry from the delta queue and how to recover them.

Thanks

Priya