My Ultimaker 1 with a heated bed doesn't print good first layer lines at all. The single lines keep detaching from the printbed, no matter what nozzle or bed temperature or the height of printhead from printbed. I cleaned the printbed thouroughly, too. It worked a while ago, I don't know what I am doing wrong.
Data:
Ultimaker 1 with Heated Printbed (Glass) PLA @ 200°/60°
This is how it looks like after removing a print (one and a half layers) from the printbed.
It is quite thick though.