what could be the possible reasons for my jelly not setting properly? I had high hopes after reading that it should set very easily.
:o
Unless they're very over-ripe, redcurrants are normally good setters.
Pectin (the setting agent in fruit) can also be diminished by over-cooking: that's why you try to make the final phase (when you add the sugar and go for the boil) as quick as possible -- and why it's a good idea to warm the sugar in the oven before adding it to the fruit.
It's also why jam pans are huge; so you don't have a deep layer of jam to cook.
Is any of this any help?