blu ray clipping

[Ramrod]

Hi Guys
I am new here so forgive me if this is a common question but i can't find it with a forum search.
I have a BD 50 player which i bought a month or 2 ago (forgive me as time just flys by far to quick) and yesterday while watching a blu ray it clipped my speakers so bad i don't know how it did not blow some of the drive units out of the casings.
I have a pair of mission 753 i's which i have had for about 13 yr's or so and still serve their purpose well so i dont want to destroy them now(i use them as rears). Fronts are kef iq 90's which i don't want destroyed either.
I remember reading about this somewhere before but can't find the articile again. can someone tell me what causes this and how i can stop it from happening again (if at all).
Many thanks and great forum.