Does anyone know GOCR (See also manual)? At the moment, I'm making some strange experiences with it.

I have written some python code which uses GOCR:

p = Popen("gocr -C 0-9 -m 32 -a 100 MyImage.png", stdout=PIPE, shell=True)
while p.poll() is None:
    (stdout, stderr) = p.communicate()
    print stdout.strip()
p = Popen("gocr -C 0-9 -m 32 -a 95 MyImage.png", stdout=PIPE, shell=True)
while p.poll() is None:
    (stdout, stderr) = p.communicate()
    print stdout.strip()
p = Popen("gocr -C 0-9 -m 32 -a 90 MyImage.png", stdout=PIPE, shell=True)
while p.poll() is None:
    (stdout, stderr) = p.communicate()
    print stdout.strip()

p = Popen("gocr -C 0-9 -m 32 -a 50 MyImage.png", stdout=PIPE, shell=True)
while p.poll() is None:
    (stdout, stderr) = p.communicate()
    print stdout.strip()

p = Popen("gocr -C 0-9 -m 32 -a 5 MyImage.png", stdout=PIPE, shell=True)
while p.poll() is None:
    (stdout, stderr) = p.communicate()
    print stdout.strip()

This gives the following output:

________6
___0____6
___0____6
___0____6
___0____6

But directly after that, I execute this command:

$ gocr -C 0-9 -m 162 -a 100 MyImage.png 
166013476

How is this possible? Does the "extend database"-modus make it smarter? I didn't extend the database in between...