Chequered patten while scanning

My photos come out at 150 dpi after scanning (Agfa ScanWise scanner). The original images show clear colors (taken off a calendar of Mykonos); however, when viewed in Photoshop the blues (e.g. especially of the sea) and all other parts of the image show a sort of chequered or 'moiré' pattern on the monitor. I can get rid of this with a gaussian blur but of course this has the effect of unsharpening the images.

Is this a flaw in my scanner, something I am missing in the scanning process, or is this an unavoidable nuisance?

What is the best way of getting rid of it in photoshop without too much blurring of the whole image?

Any and all ideas welcome

In article <251220051149200563%>,
Julian wrote:

My photos come out at 150 dpi after scanning (Agfa ScanWise scanner). The original images show clear colors (taken off a calendar of Mykonos); however, when viewed in Photoshop the blues (e.g. especially of the sea) and all other parts of the image show a sort of chequered or 'moir