Yep, Verbatim DVD-R media works perfectly on my 709, which has firmware version 3.32A. (I write the DVDs at 2x speed on a Pioneer DVR-104, using PrimoDVD software.)
As always, "your mileage may vary" as the Americans say. I`ve heard of 709 owners having success with various brands of DVD+R and DVD-R, even cheap cack discs like BulkPaq. Other people have had no luck whatsoever.
It all depends on your individual 709, e.g. how well aligned the laser is, and what firmware version is fitted (3.24 or later should work OK, 3.32A is recommended). As a general rule, if you`ve a reasonably well kept 709 with firmware 3.24 or later, and use properly authored discs on good quality (Verbatim/TDK etc.) media, you should have no problems.
Mike