Can someone explain the current state of BLOB fields and Postgres ODBC?

We have an ODBC application that among other things needs to be able to
read and write binary files to the database. Originally I tried using oid
fields, but now it looks like bytea with the "bytea as lo" parameter is
the recommended way. From my searching on Google, there seems to be a lot
of information (mostly old) that talks about oid, bytea, and lo, and I'm
now pretty confused. Can anyone clear this up for me?

When working with BLOBs we always use bind parameters and if the binary
data is over 2500 bytes, we read or write the data in chunks. This all
seems to work ok, but when writing files to the database, its returning
the warning message "WARNING: nonstandard use of escape in a string
literal". When I pull the files out, they still seem to look ok, but I'm
worried that something is trying to interpret the data instead of just
passing it in directly. Is it safe to ignore this warning? Or is it
possible that data corruption could occur?

Jon