Greasemonkey JS & Opera 9.21

Perhaps I am being particularly obtuse, but I've been looking for a solution 
to this for the past few hours and am no closer to finding one than I was 
when I started.

I am well aware that Opera provides for the use of Javascript; however, I 
cannot for the life of me make any cripts work. Not a single one.  I have 
followed every how-to and tutorial and section in the help files, to the 
letter.

Has anyone else had this same problem? I dislike Firefox intensely for many 
reasons (this is not a Firefox vs. Opera flame war starter, please don't 
make it into one) so I would rather not use it. But if push comes to shove, 
I might have to.

Any pointers would be most gratefully received.

Thanks

Colin