Toolbox "baby steps" again: what could be going wrong this time?

To recap previous work: I've got a Java program that monitors a *DTAQ for
a "wakeup signal" to poll an event file for new records. That much works,
both in a simplified test program we have on one box (V4R4), going through
host optimizations, and in the still-under-development production program,
accessing a completely separate box (V4R5) through Host Servers.

Now, I'm using a key from the event-file record to retrieve a record from
a keyed file:

    QSYSObjectPathName fooName = new QSYSObjectPathName("BOZBAR", "FOO",
"FILE");
    KeyedFile foo = new KeyedFile(as400, foo.getPath());
    AS400FileRecordDescription fooDes = new
AS400FileRecordDescription(as400, fooName.getPath());
    . . .
    foo.setRecordFormat(fooDes.retrieveRecordFormat()[0]);
    . . .
    singleKey[0] = (BigDecimal)(eventData.getField("BIKEY"));
    . . .
    fooData = foo.read(singleKey);
    for (int i = 0; i < fooData.getNumberOfFields(); i++)
System.out.println(fooData.getField(i).toString());

(The names have been changed to protect the innocent)

It works in the simplified test program, printing out a list of the field
values, but not in the still-under-development test program (it doesn't
appear to be blowing up; it just gets NOTHING).

--
JHHL