Matshita UJ-822Da problems...please help

My VAIO computer has a Matshita UJ-822Da DVD/cd writer. Up until now, it was working perfectly. But for a few days, every time I try to copy a DVD disc, I get the following message.

Creating the image for burning
Creating image completed successfully
Burn process started at 2x(2,770KB/s)
Matshita UJ-822Da
PMA update failure
Writing short lead-out
Matshita UJ-822Da
PMA update failure
Matshita UJ-822Da
Could not perform end of Disc-at-once
Burn process failed at 2x(2,770KB/s)

This is not consistent. On ocassion, there is no error and I manage to burn the DVD (the same that would have earlier failed). Also, I have no problem copying CDs. The problem is only with burning a DVD.
I’m not really tech savvy at all.
Could someone help me with solving this problem?
Thanks.

Try to clean the drive, it may help.