Ok - maybe standalone is a problem. But what about dvd-rw media? It can be read only on the device the writing was done. No other device is able to read - detects as blank.
BTW: today made the test with DVD+RW media. Liteon and standalone had read written disk perfectly. Media was also from Verbatim.
So I am in complete mess.
An also dvd-r disk standalone was not able to read was written using 4x speed. If slowering down more I guess I will have to write with hammer