Have experienced this on numerous occasions Roland,s advice is sound but the only problem is if you have levelled the caravan it will alter your level and in the case of my van due to the size would have to re hitch to get it level again.I now on arriving at the site release stabiliser (just pull Winterhoff up to first position) then drive to pitch and find that this releases the stabiliser pads and the van comes off straight away.The van is still firmly attached and will not come off all you are doing is releasing the stabiliser .Hope this helps as i know what a pain this can be
Cheers John