I had some problems printing a solid layer on top of an infill layer. After doing many tests with different temperature, speed and extrusion I figured out that my red filament is just crap. It looks much better with yellow or White (abs) filament from another vendor …
Is is slic3r 0.9.9 (latest)? There’s a bug in roofing in that version. It treats the first layer on top of infill as a bridge, except they forgot to change to the bridging speed, so the threads of plastic tend to break off rather than stretching across the gap if you have reasonably high print speeds set.
Make sure you have calibrated the filament diameter properly. You said you’d already checked E steps, but proper input diameter is equally important.
This looks like an extrusion problem to me, assuming it’s not what @Whosa_whatsis is describing.
When i had prints looking like that, i had to add a fan to my printer. Just a small fan blowing over the top of the print.
In my case it was only on with the top layers.
Looks like the red is running too hot / too thin / too fast. You might want to print 100% calibration cubes and compare. The fill factor - if the red is not as dense, you’ve got to bump up the extrusion rate.
@Whosa_whatsis
I tried slic3r 0.9.8 as well, same result. I really think that the filament is crap, the adhesion of the first layer is bad as well.
@Mano_Biletsky_Open_M
I have a small fan already. I even tried with an additional usb fan but it did not help.
And can’t you lower the nozzle temperature?
Have you tried lowering your nozzle or raising the extrusion amount to verify that the reason for the poor adhesion is not because you are under-extruding? It seems like that’s very likely.
@Joseph_Chiu
Yes, I tried raising the extrusion (increased Slic3r Extrusion multiplier), It made it even worse.
Uhm, perhaps you should try decreasing?
Indeed! Decrease!
What was the problem? poor quality filament? could you describe the brands or vendors ?
The filament had a poor adhesion, but in addition my extruder did not pull the filament evenly. After cleaning the hobbed bold it looked much better.
tnks for the response, for the record i have experienced some poor filament quality, and i dont know, it seems that it was just bad luck, cause all the reviews for octave brand are good. just me experiencing troubles 
…