Hi,
We had problems with a JVC BR-D750 deck trying to export to tape from Premiere. Not quite the same problem perhaps, but the following notes may be of some help.
After switching over to 9pin remote, have you checked any available menu settings. The JVC has {9 pin device ID} and {Controller select} which need to correctly set. I assume that the Sony has something similar.
The above did not solve our problem so I installed proVTR (a legacy from a Digisuite system). It has to be connected to the computers’ serial port by a convertor cable. It was seen as a device control option by Premiere and seems to work fine so far.
Hope this helps,
Geoff