[Discuss-gnuradio] Clock block slow in position satellite calculation

[caruiz.ext]

Hello,

I have this flowgraph in GNURadio: 
http://i1281.photobucket.com/albums/a515/Carlos_Alberto_Ruiz_Naranjo/esque_zpsd89166da.png

-> Green: calculates the signal delay of a satellite.
-> Yellow: a clock with a second precision.

If I run the clock separately I can see in the WX GUI Number Sink that 
it works. (0,1,2,3,4... each second)
But if I run the entire flowgraph I can see in the WX GUI Number Sink 
that clock becomes very slow. (0,1,2,3,4... each 2 second approximately)


Why is this? Any solution?

Thank you ;)