In reply to mataius:
Hold on - it's a nine-year old alloy mountain bike. Before you spend any money, go over it inch by inch to make sure there are no cracks.
Then make sure that the pull shock is still working well (as that'd probably be the hardest thing to replace).
Then if all is well, consider new fork (a bit of googling suggests that the Black Comp was cheap but ok-ish, about 1.9kg and either 80, 100 or 120 mm travel). To replace with similar or better it's probably going to be a rockshox Recon or Reba.
If you need it, the user manual is still on the Manitou website - you could give them a service before replacing:
http://www.manitoumtb.com/assets/Owners%20Manuals/2003%20Black%20Owners%20M...
I think the Genius had the 120mm travel version, but there are some measurements in the user manual to check.
Or consider new wheels - Lighter, stiffer, tubeless? Superstar components, or Merlin Cycles or handbuilt?
Oh, and new tyres that are more specific to where you ride might help - if you survive the conflicting information overload that follows any "what tyre" question on the internet!