Sounds like the mot tester is being a bit picky, if it's only a slight wobble! might just need the fixing bolts tightening or if it's loose on the runners, you may be able to squeeze them with mole grips.
sid
August 2010
could be fittings loose, if ok you will need look at the fitting area to see if there is any corrosion present, might need a plate welding on.
hope it helps
August 2010
I can answer this question...
i have a slight wobble on the drivers seat in a peugeot 206 ?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.