Changing file pointers ?

Help ! We are in a quandry. We have a program that looks at a non-keyed
physical file via a keyed logical. The program reads file thru the logical
and passes the record key to a second program which access the same physical
thru a different logical. When it returns to the first program, the first
program says that it cannot update the record without a prior read or chain.
The only thing we can think of is that the file pointer has been changed
somehow. 
 
These are OPM programs (JDE) running in the default activation group.
Scoping is by activation group. ODP is not shared.
 
 The truly weird thing is that this program has run for months with no
problems, has not been changed recently, but is dumping out. (This is a
truly ugly bear of a progam. 2150 records not including the JDE copy books.
Only one programmer maintains it and she hasn't been near it.)
 
Anyone have any ideas ?
 
Thanks,
Cyndi B.
Boise, ID
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