Epson iscan issue

I have Epson V330 Photo and use the iscan packkage, it works great but have a issue.

In the iscan scan dialog window there is a option for unsharp mask and if i check or uncheck that it seems to work as it clearly visible effects the preview scan.
The issue is that i don’t see any change in the saved file (i use tiff) with or without unsharp mask checked?

Is this a bug, or does my V330 not support this option?
Or does it only effects the preview scan but not the saved file?