[Red Herring]

Do they go back to "cardboard" even if you haven't moved the bike? Sometimes the sliding pins on the calipers get worn allowing the caliper to rock and go off square with the disc. When you apply the brakes the caliper needs to re-align itself before working and this can take a squeeze or two. Easiest way to check is to ride the bike slowly up the road, come to a halt without using the front brake then see if you can rock the caliper by hand.

If you are refilling the brake system from dry, ie:you've drained it, then it can be a right bitch sometimes to get the fluid to start running down through the master cylinder, the air in the pipes keeps going up (it would, air rises). Either take the calipers off and hold them above the master cylinder until you get some fluid through it, or (I joke not) blow up a condom and put it over the top of the fluid reservoir, open the bleed nipples on the calipers and the pressure should push the fluid through for you. Also helps explain to the wife why you keep a three pack in your toolbox!