Correctly getting data from serial output (Adafruit Geiger Counter)

Alright, im trying to log data from a geiger counter (http://www.adafruit.com/products/483#Description) onto an arduino using a serial output, but im having some troubles. The method I am using works for the most part, but after about a minute of running, it starts to randomly add in some weird ASCII values, so I think im doing something wrong… For example, correct data looks like this:

CPS, 2, CPM, 26, uSv/hr, 0.14, SLOW
CPS, 0, CPM, 25, uSv/hr, 0.14, SLOW
CPS, 0, CPM, 25, uSv/hr, 0.14, SLOW

But after a while it starts to look like this:

C#PS, 0, CPM#, 27, uSv/#hr, 0.15, #SLOW
CPS,# 0, CPM, 2#6, uSv/hr,# 0.14, SLO#W
CPS, 1,# CPM, 27, #uSv/hr, 0.#15, SLOW

I’m using this on a board that is tracking 5 other sensors, so ill only post the part that tracks the geiger counter (ill attach the full sketch):

void logGeig()//Method for logging the geiger counter
{
geig = SD.open(“GEIG.txt”, FILE_WRITE);//creates/opens a file on the SD card
gSerial.readBytes(gBuff, 10);//Loads gSerial data into gBuff: I think this is the wrong line of code to use here…
if (geig) {//if its open do this
geig.print(gBuff);
geig.flush();
}
geig.close();//Close the file
}

If you have any suggestions on how to get more reliable data that would be great!

_1File.ino (4.83 KB)

Actually the whole sketch seems a bit broken... It seems to only log onto the "geig.txt" file and not the other one... Does anybody know why this is happening?