OTL crashes when updating second BLOB in row

We experience crashes using Oracle 11G R2 and otlv4 under windows. We have a table that has, amongst other things, two nullable BLOB columns. We experience crashes inside otl when we're trying to stream the second BLOB to the i/o stream.

Is there anything special we should observe when doing this?

BTW: all is fine if we only update one BLOB at a time.