Hi Seeker
Yes I was having trouble with it. Dark subtraction helps but it often leaves a greenish colour instead, and I have to reduce the opacity of the dark frame in Photoshop anyway otherwise I get coloured spots all over any nebulosity in my images from the dark frame.
A much better thing is Gradient exterminator
http://www.rc-astro.com/resources/Gr...tor/index.html
It magically gets rid of most of the amp glow in one go, as well as any vignetting. Its the next best thing to a proper flatfield. I use it all the time and often dont bother dark subtracting unless its a very long exposure (more than 15 mins for ISO 1600)
Scott