Thanks falingtrea, that is a good idea.

In fact i was going to change my code to do that by i remembered that one of the ports i mentioned is one bi-color led ( green and red with comon anode ) and the green one doesn't light up.

This was what i changed :

PortA.7 and portB.4 added a 2K resistor in series.
Remaining ( working ) ports...left as is ( meaning...without resistors )

Result :

Now all led light up normally !!!

Still, i have to mention the hardware feature in these 2 ports that produce this behavior.

I searched the 16F88's datasheet and i could not find anything that could link to this .

.