What setting did you set on your grinder?
Are you using presurrised basket?
Try set the grind finer and see if it helps. Try different settings each time til youve found your favourite.
I haven a Ikon as well and am using 13 on my EM480, however Ive found the readings on 450 and 480 are different.
At work we have a EM450 with setting on around 6 which is similar setting on the 13 for my EM480. (anyone please correct me if I am wrong)