This is from Computer Music's 202 Power Tips:
Can the cans
Never use headphones to mix. Contrary to popular terminology, there's no such thing as stereo headphones. When listening through two separate earpieces, music is heard 'binaurally' and the effect is quite different to listening through speakers. It makes accurate mixing all but impossible.
maybe this is what you experienced...?

Quote Originally Posted by elyzium
if i'm listenign to some banging trance or techno or whatever on my hi-fi and like what i hear, then try writing similar material so it sounds just as good on my hi-fi speakers, isnt my track then going to sound the same in a club as said record would???
Probably not, because the tracks you would try to "simulate" in sound quality wouldn’t be perceived accurately through hi-fi speakers in the first place... something to do with the frequency response not being flat in hi-fi's... so they add "things" to the original sound.

I'm not really sure about what I just wrote so I hope someone else will reply to this too... for your sake :D