I recently got Sony TX laptop equipped with Panasonic's Matshita UJ-832D drive. Burns very well everything but DVD+R DL. On DL it make 3 coasters out of 4 attempts. Media I used was both Verbatim and Fujifilm.
Most frequently it throws some I/O error message at 50%, where drive switches layers, but it also happens in other stages. I tried it with BurnImg, Roxio Disk Copier, etc. - the same sh*t happens.
On SL DVDs it works perfectly.