positive IgG in ChIP - (Oct/23/2007 )

Hi, I have been doing ChIP since a few months now but I recently got a problem that I did not have before.
I am getting positive IgG from my sample after PCR (the Ct is 27 almost the same of my K27 trimethilated)
I use the EpiQuik kit form epigentek and it worked fine before
How can it be?
I use around 8 ug of sheared chromatin as starting material, is it too much?
I have been trying washing my wells for more time but this did not help.
any suggestions?
thank you

I would like to try by decreasing the starting material.
Some times washing with low salt also works well. I use UPSTATE kit with magnetic beads from Active motif and usually they work well.
Hope this helps.

thanks for your help
I will try to do so
it is just weird that until 2 months ago using 8 ug was fine
by the way, we ll see
thanks again