¿How to make VHS-C tapes play well on AG-1980 VCR?

I have 3 VHS-C and 1 SVHS-C. My AG-1980(like new) VCR though it plays all my other VHS tapes very good surprisingly it won't on the smaller version (with adapter)... It shows slight color distortion. Does anyone here has a solution? my SLV-R1000 can play VHS-C tapes normal but the quality of the AG even with color distortion surpasses it in detail.

SLV: http://imageuploads.net/ims/pic.php?u=14411xOyeV&i=125561
AG: http://imageuploads.net/ims/pic.php?u=14411xOyeV&i=125562