I have not used FoxFire, but in other non-oracle (odbc)report tools, that error message can have one of several causes.

A leading '_' or number not enclosed in quotes " ie. _smdba_._cust_ intead of "_smdba_"."_cust_"
A reserved word in the select not quoted i.e cust.sequence intead of cust."sequence"
A join not quite perfect

WHERE
cust.dept_seq = dept."sequence" +

istead of
cust.dept_seq = dept."sequence" (+)

Punctuation can be a problem as well, but rarely.

It is also possible the owner of the query does not have rights to the field, but that is rare (usually)

If you need, send me the sql statement and I'll try and spot the error.