NC4 Exif Stripping?

Hey,

Ive been fooling around this evening with the wonderful script posts that Regrit, Rory, and others were so generous in sharing with the forum. After getting the script to load I noticed that some files lacked the ISO rating or the shutter speed. I have tracked the problem to the point when I save in Nikon Capture in my workflow. (my workflow begins by opening the image in NC and editing WB and curves, then saving as a Tiff, and finally opening in PSCS for final corrections, i.e. sharpening, NR, etc.) Apparently when I save the NEF file as a TIFF, I loose EXIF data. Can anyone explain this? Is ther a way to remedy the problem?

Thanks,
Raymond