If the shackles/spring hangers are what you are talking about then I had this happen when I put some tough dog springs on my lux. It was to do with the spring being more arched than the original, hence the eye where the shackle inserts is in a different position relative to the chassis. This will draw the shackle forward relative to its original position.
It can be a problem because there is the possibility of it inverting, the spring moving in such a way that the shackle ends up sitting horizontally against the chassis forward of the perch it pivots on. This is bad, but not that likely to happen.
I would think that as the spring settles the shackle will eventually move rear ward. You could try to increase the rate at which is settles by carrying some substantial loads for a while. You could also try loosening the spring clamps to allow the leaves to loosen up a bit. Good idea to keep an eye on this as if the spring is too loose it can lead to axle wrap etc.
If the ends of the individual leaves are not greased or do not have plastic looking inserts (made of teflon type stuff), then you might consider altering the ends to allow them to move easily against each other. You can either pack them with grease (temporary measure) or buy some teflon/slippery plastic material and stick them between the end of each leaf springs and the spring above it.
Another alternative is to remove the third spring from the bottom (if it is a six leaf pack). This will lower your lift, but improve articulation. You can regain your lift by putting a longer shackle on the rear, but this might require certification.
All this is assuming that you have been given the correct springs and that the installation all went according to plan.
, thanks heaps. After some fiddling last night, every time I lowered the truck down from the hoist the shackles inverted 
, to over come this we guided them to fold the correct way, and then every time after that they keep folding the right way 
if it happens without load on spring, ie when you had it jacked up, you could imagine dropping off a ledge or going through a hole and one wheel up in the air, the spring will have no load on it and the likelihood of the shackle inverting when getting loaded up again will be high..
