Bored at work so had a search for trials on ebay and come up with some very interesting items and prices!!
http://cgi.ebay.co.uk/shogun-trials-bike-/200518072305?pt=UK_Bikes_GL&hash=item2eafcef7f1
http://cgi.ebay.co.uk/26-inch-frame-reefer-mission-trials-bike-/130427503464?pt=UK_Bikes_GL&hash=item1e5e15c368
http://cgi.ebay.co.uk/onza-T-mag-trials-bike-/150490830413?pt=UK_Bikes_GL&hash=item2309f3d64d
http://cgi.ebay.co.uk/BASE-TRIALS-BIKE-/260652565411?pt=UK_Bikes_GL&hash=item3cb01a83a3
God I'm bored!!
Suppose he does have a point, if a trials bike had to have a set amount of components it would be a bit more accurate but you've gotta think that people who run maguras have more components than those who use discs, and the same again for single speed against multi geared, and then you could run quick release skewers to add another component in, bar end plugs, seat, no seat, etc.....
Sounds like either its got a bit of air in and needs a bleed or you've contaminated your pads on something.
I had the same problem with my mono mini, ended up selling it to find that the problem was the disc, don't know what happened to it but it just went awful!
Get them from here http://www.heatsinkbikes.com/.
They're pricey as when you buy them the first time you get some CNC machined backings which hold the pads square unlike normal plastic ones which will bend if your brakes aren't setup perfectly straight. But when the pads wear out you just buy the material, remove the old worn out ones and just glue the new stuff in the backings!
Have a look on the site as they explain it a lot better than me!! I've got the yellows on both my bikes on the rear and I wouldn't use any other magura pads to be honest!
My first bit of advice would be to ditch them as standard magura black pads are terrible!
I'd highly recommend some heatsink yellow pads although they are a little pricey the first time you buy them but cheap every time after!!
I'd give the headset a try first, and it is like you said loosen stem, tighten topcap then tighten stem.
The brake pads may move slightly but I wouldn't think it'd be enough for you to notice it really, what pads and clamps have you got??
Is it a brand new bike as it may be a bit of play in the bearings or something.
Finished putting together what I can of my lovely Echo Control that I've picked up off Onzatrip.
Just waiting for my rear silver Echo TR rim to be built onto the Viz anodized blue hub that came with the frame and she'll be ready to go!
Be getting a bit of a haul over at christmas though if I can blag some tarty vouchers (missus goin nuts over how much I spend on my bike) so will hopefully get a rear TR hub and blue rim to match the front, blue urban bashring and maybe a new headset but will see how this First one holds up er, first!
Will get better pic when my wheel arrives and goes on with full geo!