Soldiers Beret, why can't films get them right?

Every time I see a British soldier in a film he's always wearing his beret like a bloody pork pie sitting up on top of his head, no real soldier wears his beret like that, don't films get proper advisers anymore?
I was a soldier, and we used to spend days shrinking and shaping our berets until they fitted like scull caps .No "pork pies" for us, and it was all the regiments not just ours, that was the way it's been done for years, you would think by now they'd start getting it right.

Braveheart.
I suppose we must blame Hollywood, after all getting historical things right isn't their strongpoint, take the film Braveheart, they have the Scots weraing kilts, about 400 years early, the British soldiers weraing uniforms (they didn't in those days they had normal clothes) Then theres the Scots paint thier faces blue, err that was in Roman times guys, do try to keep up.  The other major error is the Stirling bridge, it played a major part of the real battle but is pretty much left out of the film

U571
Here again Hollywood screwed up, first off the Americans never actually sunk or captured the real U571 (it was sunk  by an Australian plane off Ireland in 1944) Secondly by 1942 several Enigma machines had already been captured (The first capture took place in February 1940, when the U-33 was taken by HMS Gleaner off the coast of Scotland.} Thirdly the Enigma had actually been deciphered almost a year before this film is set – and seven months before the US entered the second world war.
The film seems loosly based on  Operation Primrose ( 6 may 1941) where HMS Bulldog (a British navy ship) captuerd an inigma machine and more importantly code books, to add insult to injury they had the cheek to praise the real sailors who captured the machine, if they cared why make up a load of rubbish about the story in the first place.