
I found this page on sonys website
http://www.npe.sony.co.uk/faq.html
It says about halfway down
Will Smartlink work with non-Sony devices?
Smartlink may be referred to as Megalogic, NexTView, T-V Link, Easylink, AV.Link, CinemaLink, or Q-Link. The VTX-D800U will operate any device which provides the compatible interface.
It also then later says
I have a Smartlink VCR and the Smartlink function does not seem to work
The first thing to check is that the Smartlink feature is enabled on both your VCR and on the VTX-D800U (Menu->Settings->Picture->Smartlink). Secondly, check that the VTX-D800U is connected to the Smartlink compatible Scart of your VCR and that the Scart lead you are using is ‘fully connected’. The Scart lead provided with the VTX-D800U is ‘fully connected’. The present range of Sony VCRs do not fully provide the Smartlink recording feature that has been designed into the VTX-D800U. The software for the VTX-D800U was updated to provide additional suitable signals for the present Sony VCR models SLV - SE 830 and 730 to correctly operate the Smartlink feature. If the software version of your VTX-D800U is the original 1.04.01 and you have a Sony VCR, then we advise you to switch off the Smartlink feature in the Set Up menu of the VTX-D800U until you receive the updated software.
So it looks to me that the Q-Link system is trying to communicate with the smartlink or Sharps equivalent (I have the 28DTX10 and a Sony SE 730 VCR), but software could be causing a similar problem as to what happens to the Sony VTX-D800U TV described on the Sony website.
This probably means its only compatible with a Panasonic VCR/DVD-R.