DV input to DV deck

Dear Fix Ya fixer: I have just purchased via E-bay a used Sony DHR-1000 recorder- to replace my Panasonic DV-2000. The Sony checked out OK until I began a DV dub From my editor (Applied Magic's Screenplay apppliance) to the Sony. The Sony just didn't seem to like the Screenplay signal. It would lock on for awhile, then drop the recording. Then it might come back for a bit, and drop off again. I switched the Screenplay (SP) firewire output to my old Pana 2000 and dubbed that way; got the show out; then investigated some more. Sony's online manual for the 1000 sez: "When you connect the other VCR using the DV jack, the data, index signals and contents of the cassette memory are not transmitted." I assumed that referred to timecode and cassette chip contents, and was standard for all ieee transfers. Or- does it mean that this model Sony might have a problem with some DV input, including input from my Screenplay, a problem not shared by the Panasonic 2000 deck??? Anyhoo, I began a check: On bootup, with firewire connected, the Screenplay signal was steady on the monitor from the recording Sony until the point where the SP graphics menu pops on just prior to its main workscreen menu. At that point the signal (and the resultant recording) began to pop on and off intermittently and for random lengths of time- like it couldn't stay locked on for long. It also drops off when inserting a cassette, on cueing the record tape, and other moves. Jiggling or flip- ending the firewire is no help. The non-signal that is recorded on the tape in the Sony during these intervals is a plain grey screen. However- the Sony deck DOES like the signals (both tape and camera) from my Canon XL1 DV port. When I move the firewire from the SP to the XL1, the signal pops right up on the monitor and holds just fine. The recording on tape is also normal. And feeding signal from the Pana DV2000 to the Sony 1000 also works normally. The tape I fed was a copy made on the Panasonic of the same SP storyboard that would not record well when sent to the Sony directly from the SP. My questions are: Have there been similar problems observed with this Sony model? If so, what is the cause and/or solution? Without such feedback, in order to find if I have purchased a defective machine (or one unusable with my system) I will have to find an identical Sony deck to test with the Screenplay. I still can't figure why recording to the Sony DV should be so troublesome compared to Pana 2000. (Granted, the problem could be with the output of my particlar SP-- but the camera (XL-1) and the Pana deck both accept the Screenplay DV output just fine. Thanks in advance, Mike.