I have an MX100 and several universal remotes and none of them will operate this VCR except the one that came with my Sony receiver. However, I don't get on with that remote so I have used the learning function on a OFA Cinema7 which works fine now that I am aware of the fact that a learnt function can be assigned to any key (despite what the manual tells you - see Cinema7 FAQ's on this website)
JW