In article , Nick Maclaren
writes

Odd. However, following on from another thread, sports are fairly
common in most plants, and it isn't impossible that you have one that
is effectively self-sterile. If that is so, replacing it by another
plant would work. But I doubt that explanation.


Regards,
Nick Maclaren.


Not sure if it will help, but when I moved to this house in '79 there
were several blackcurrants bushes that didn't seem to fruit.
I wanted to move them anyway so dug them up and planted 5 hardwood
cuttings, just shoving the stems into the ground (I did add a bit of
sharp sand to the trench)
They grew and fruited fine.

Might this be a solution?
--
Janet Tweedy
Dalmatian Telegraph
http://www.lancedal.demon.co.uk