Weird steering problem??

[wence]

Happy new year to you all.
I have had the front forks worked on and the bloke went over the bike checking it.
Among other things he tightened the headstem bearings.
Now I like the steering to be light and be able to move freely.By this I mean , if it is on a stand and I move the bars to the centre I like the bars to drop back to the side.
The forks are better in that I can hit things a little harder and now have a little movement left on compression and rebound.
The problem with it now is that it is really unpredictable in rocks,seems to want to follow and railroad any sort of rut etc and generally feels really unpredictable.
My mate nailed it when he said it feels twitchy but steers slow.
I have mousse tubes front and back and had them before the work was done.I did pull out the front mousse and stuff a bit more in the tube to give the front a little more pressure and this seems to have helped a little but the problem is still there.
I have gone through and reset the axle by doing up axle bolt then tightening
one side and then bouncing front and then tightening up the other side.
I will change the front tyre next as it is fairly old and has seen a season last year.Come to think of it I may have turned the tyre around as it was worn to give me the edges again which may be causing the problem?
I am at my wits end as it feels good but bottoms out a little easy and just won't give me the usual gasser planted feel???
Please help......
Cheers Mark