Durgesh is right… Why you typically lose rows for no reason and aren’t prompted by BO that you have partial results, modify your fetch size. It’s possible that your fetches returned out of sequence, or you had bad packets.
In Oracle there used to be parallelism query issues, but those just returned incorrect aggregated data. Everything else I’ve seen along these lines are from lost packets.
(ie. Fetch size is 5, and you have 16 rows… After receiving the 4rd packet of 5 rows, you may received a “disconnect” prior to the last “complete” packet arriving. Depends on how the database is interacting too (sync or non-sync)).
Also check out this topic that is somewhat related.
-RM
digpen 
(BOB member since 2002-08-15)