Corrupt artifacts

Hello!

I'm using teamcity to build a project but the output binaries(.elf) in artifacts are corrupt. The build runner is executing a python script which in turn executes a shell script in cygwin that starts the make process. If I run the python script by it self in the build agent then binaries are correct, but when executing it from teamcity the binaries are corrupt. I know this is a odd one, but any ideas or suggestions would be much appreciated.

More info:

Agent Os: Windows XP
Compiler: Freescale Codewarrior HSC08
Build runner: Command line
Command executable: C:\Python27\python.exe

Snippet python script:

def buildBaseBandBinary(cygwinPath, path):
  aPath = os.getcwd()
  #convert to Unix path
  uPath = "/cygdrive/" + (aPath[0:1]).lower() + (aPath.replace(aPath[0:1]+":\\", "/")).replace("\\", "/")
  uPath = uPath + "/" + path.replace("\\", "/")
 
  f = open("rTemp.sh", 'wb') #make shure binary so that line endings are preserved
  f.write("#!/bin/bash\n")
  f.write("cd " + uPath + "\n")
  f.write("make -f product.mk  cleanall\n")
  f.write("make -f product.mk\n")
  f.close()
  print os.environ.get('PATH', '')
  os.system(cygwinPath + " -i -l " + aPath + "\\rTemp.sh")