this is a different issue from the gear cable problem... if you look at these photos...
http://www.flickr.com/photos/26939952@N03/2603804351/in/set-72157605774209701/

the first one shows a long screw that goes in the hole in the center of the handle bars (pic 2). This pole is loose and will not tighten up it has been this way since a wheelie crash incident on the way home from the pub (no one was harmed!!). i was advised that if i turned the bike upside down the ploe would screw back in however this  is not the case.
what is this pole? why will it not screw back in? is it safe to keep riding the bike? (i do anyway....!!!) and how on earth do i fix it.
the final picture is of my bike i plan to really clean it up soon!!!!
p.s it is missing the little dragon badge from the front.... any idea where to find a black and white one??

Hi, This is the stem bolt, it screws into a nut in the forks to stop the handlebars turning without the forks moving as well, it wont have fallen out as the front brake caliper bolt will have stopped it.

Loosen the headset lock nut (first nut under the handlebars) then put the front wheel between your legs and try to turn the handlebars, they should turn with a bit if force and some WD40, keep moving them from side to side and pulling upwards and they should come out. Turn the frame upside down and the nut should fall out. Put the stem bolt back in the bars, attach the nut to the base and give it a few turns until the nut lines up with the split in the handlebar stem, put the handlebars back in the forks and tighten the stem lock nut up  ;)

i'd loosen the headset nut right off as there is a ball bearing which sits in the slot in the handlebar stem (the slot in pic 2 ).  although if the bars have been off in the past the ball bearing will probably be lost.