I am using the Epson 4990 that I have had for about 9 months. It has been working great until recently.
When I scan, the preview color and density is many times different from what is imported into Photoshop.

I am using Epson's scanning software (which I have used all along). I calibrate my monitor every couple weeks using Gretag MacBeth Eye-One. I am on version CS2 of PhotoShop.

I've not made any changes in software, hardware, etc. for about 3 months. My color settings in PhotoShop remain the same.

Ideas as to what the problem is?

Preview:


Result: