Problems with SE and Epsons 2450 and PS7 w/ XP-weird stuff!

[echelonphoto]

I need to scan 6x6 fuji negatives very frequently and have found my epson 2450 to have more than enough resolution for my needs. However, I am having great problems with getting good skin tones. I was using the epson twain and trying to adjust a custom curve..but I would always get green or yellow tinits in highlights and shadows...couldn't even remove them in PS totally.

I finally tried the Silverfast SE that came with my scanner and used negafix for the fuji NPH film. My first few scans were fantastic..with a few tweaks in PS...I was getting great skin tones (biased toward blue/red), no more green overtones. Then it started to change..my next batch of negs were not as good (same film) and the old green started to return.
I tried some global color correction and this helped for a while...but now I'm back in the "greens" again. What is happening is that I can adjust my image preview for a good balance, but when the actual scan is made..it is not even close to the preview. I am tearing my hair out! What did I do wrong?

[LSI_Support]

check your color settings and the profile handling settings in PS7