Hi smilanko - I used that GPS module to build a clock a while ago. The commands to
change the GPS polling rate are:

"$PMTK300,1000,0,0,0,0*1C" // Sets rate to 1HZ
"$PMTK300,200,0,0,0,0*2F" // Sets rate to 5HZ
"$PMTK300,100,0,0,0,0*2" // Sets rate to 10HZ

Hope that helps.

Rick Comito