Insert result does not match record count

Hi all,

I am moving some data from one table to another in 9.2.4, and keep seeing this strange scenario:

insert into newtable select data from oldtable where proc_date >= x and proc_date < y;

INSERT 0 78551642

select count(*) from newtable where proc_date >= x and proc_date < y;
count
-----------
4373518938

select count(*) from oldtable where proc_date >= x and proc_date < y;

count
-----------
4373518938

So, my counts from the old and new tables match, but the result returned from the insert statement is sometimes a completely different number. (But not always.) I've checked my date ranges very carefully to make sure they match.

Has anyone else ever seen this before? Should I be concerned?

Thanks,
Natalie