Problems Mintex M1155 pads

[Dino86]

Anyone faced problems with getting the M1155 front pads to work properly?
I used to have the M1144 fitted on Black diamond discs and they were performing very well.
Now decided to 'upgrade' to M1155. I grinded the discs, ran in the pads according to Mintex adivised procedure but I keep having very early brake fading.
After burnish, I let the pads cool down.Than, I made few smooth brakings to get the brakes conditioned.Than I performed 3 times hard braking from 100 until 40kph and only applied smooth acceleration in between to allow some cooling. At 4th braking attempt from 100kph, at around 70kph, Brake force drops drastically and pushing pedal harder and deeper doesn't make any change... very scary... it feels like the car will never stop!!!
I tried a second set it seems bit better but still early brake fading occurs.
Can I use the same discs as with the M1144 pads? Or, is this causing the poor performance?
Does it just need more run in?

Thanks for your advise.