So, as the subject says, I have some 1056B03 remotes -- one with no JP designation, and another one with JP2 silkscreened by the header. See pictures below.

Have any of you encountered these, and are you able to use a JP1.x cable to read from or write to it? My attempts to do so have failed. Same cables (diygadget serial cable, and another USB), which work on the 1056B01 JP1.3 remote, don't work with the 1056B03 remotes. IR.exe reports "Failed to open JP1.x interface" with these. Manufacture date on these is Dec '10 and Apr '11 for the unlabeled and the JP2 labeled remotes, respectively.
I haven't got a Tommy Tyler cable to test with at this moment (but looking to get one to try out -- but curious to see if anyone else has tried yet).
Any thoughts?
Ben