could someone confirm
 

If I focus on an explorer item and +J which is supposed to be jump, the jump dialog opens but the focus, i.e. what will be jumped is the parent of chosen item. Thank you.

the focus in that dialogue is on the last item you used for jump

Quant, thanks for reply but I don't understand what you've written. Is jump then used to jump back to the last item? Is that the purpose of the command? If not, what is the purpose of the command. I must be missing something.

the purpose is to jump to another location (possibly far distant) in tree, nothing else. If you want to move back and forth, then you could open the item in another tab (choosing "new tab" in that dialogue).

ah yes... now I've got it. A mental block I think. Thanks.