was doing a shoot last weekend with my D7000 , a nikon SB800 and using a yn622N tx / 622n as a trigger. for some reason part way through  i was getting a delay between pressing the button and the camera taking the shot. Immediate raction was i had accidently selected the delay shutter opt. which i have sometimes used but when I checked it was set to off. I then noticed that when pressing the shutter the flash was VISIBLY firing 2 or 3 sort of pre flashes at slightly reduced power then the flash would fire at the set power and the shutter would operate. I did a quick check but couldnt see anything obviously wrong so just carried on not wishing to spoil the flow.   When i got home and set up the same the following day all was back to normal. Any ideas why this may have happened? as my main concrn is a) not liking the delay and b) dont want my batteries runing down any quicker than they have to!

eTTL?

The meetering preflash for eTTL doesn't cause a noticeable delay.  This sounds more like red eye reduction got switched on somehow.

You guys guessed correctly, just checked the files in ViewNX2 and sure enough , half way through the shoot Red eye reduction was activated,   no idea how, as I have never used it  but will go check it out  and find out how it was set / how to turn it off if it ever happens again. Just hate things happening I dont understand.    Thanks for your help and time guys !

This is how these forums are supposed to work!

Gosh, golly, wow! Info I can use and thoughtfully presented.

Continued success to all.