Comment 3 for bug 596064

I and Abhishek are working in the same lab setup.
Here are the answers to U'r Q

$ testparm -s --parameter-name='disable netbios' 2>/dev/null
$ echo $?

rka-29@rka-29-desktop:~$ testparm -s --parameter-name='disable netbios' 2>/dev/null
No
rka-29@rka-29-desktop:~$ echo $?
0

Also, on the machine that fail to start nmbd at boot, does starting up nmbd manually after boot (sudo start nmbd) work with an uncommented prestart script ?

Yes.