It definitely works. I bought a MC37LT remote for my NH700 about a month back. I got it off Ebay (from China) for 10 GB pounds. Arrived within a week and offers full functionality, although you need to find a manual for a different MD that uses this remote (NF810) to get the instructions.
May, I have had this problem before with my NH700. You have to make sure Sonicstage is running before connecting the USB to the MD, otherwise it is recognised by windows as a storage device, but not seen by Sonicstage.
I've just seen an MZ-RH710 for sale in Dixons in Leeds. Priced at £99.98. I asked the assistant if they were planning to stock the RH1, but he didn't know. Maybe Sony are trying to push the technology again.