poor print quality IP4850

I print on matte coated 128gsm photo paper - same stuff i've been using for years with my now deceased IP4500.

If i print anything with small white text on a dark colour background it's totally unreadable, the higher the print qualty settings the worse it gets! Only setting i can use to make it barely readable is to set it to plain paper at the lowest quality setting - obviously this is not acceptable.

Am i doing something wrong here? it's a brand new printer using Canon inks. I used my 4500 for years with perfect results every time, but i'm getting close to returning this printer after one week!

out of interest i dug out some old semi gloss photo paper and even on the lowest setting it comes out looking mint! So it would seem that my printer just doesn't like this paper which is a shame.