Le problem avec mon Citroen XM:-)

[rumpelstiltskin]

Ok,low mileage(70,000mile)Xm sd 2.1(Mark 1)turbo diesel i bought recently(yeah,why?)has a small problem,this car has wanted for nothing in its life and has a massive history and a barrel load of receipts,everything on this car at one time or another has been replaced,anyway,when the car is on the normal ride height setting(or the high setting for that matter)after i have switched the car off a minute or two later the car will drop suddenly,usually at the front,then maybe a little bit more,then stop,height correctors and everything else have been replaced to do with the hydraulics over the last two years,anyone any ideas?Someone in the past suggested to smear a little LHM fluid,ooh missus,over the struts underneath the gaiters to see if this would stop the sticking,but it hasn't?Anyone any ideas?