Teac DV-516E - 256 or 512 cache - DVD-R Yes or No

Nero tools report it has 256 kB Cache, PlexTools too. On the package there is written 512, but i found on TEAC website, that there are versions with 256 kb and that they support DVD-R. My Nero Tools reported (ver 5.5) it doesnt support DVD+R, now (ver 6.0) they say yes its supported. But none of them is saying it supports DVD-R. Has anyone simmilar experience? What is this drive really capable of?