GPS/Location lost when screen is off??

Hi!

I used to have no problems with this situation on any of my previous phones:

In apps that uses gps, like runkeeper, i get very fast gps lock.. but, then, once I disconnect the screen, the "location" seems to be turned off.. The gps track stops counting. When I turn the screen on again to check what is happening, the phone instantly gets gps lock and registers that new spot. Basically what happens is that I will get a track but, instead of having the full track, I only get "straight" lines between the points the gps locked when i turner the screen on to check what was going on..

I have the location in high accuracy..

Any ideas?

Thanks!