What's wrong with my Benq DVD LS DW1655 BCHB


When I record 1 dvd +rw (optodisc - Primedisc) the led blinks 1 time, goes off 1 second and it comes back to blink, goes 1 second off and back successively until the end of the writing.

Note: Writing always finishes successfully but when I go to make the test of quality of the Nero the Pif errors exceeds the scale arriving 50 in a limit of 16. This happens with Prime disc +rw, memorex+r, bulkpaq-r. When I record 1 dvd +r (mcc 04 - verbatim) led blinks intermittent (like should be) and thus successively until the end of the writing with Nero successfully and pif errors of 7 in 16. Perfect writing.
You can say that the problem are from the brand of dvds, but when I bought the recorder it recorded all dvds intermittently and now writes fine only the best ones.
I tried in other operative systems and is the same thing and I tried in others software of writing as the Ulead and makes the same thing.

What do you think it is?

What can I do?