testparm ignores configuration file setting

Running testparm on an input configuration appears to ignore a 'browsable = yes' setting made in the configuration file.

The output of testparm appears not to honour two settings made in a test configuration file;

under [printers], the input file has:

[printers]
...
   browsable = yes
   browseable = yes
...

while the output of testparm has:

[printers]
...
   browseable = No
   browsable = No
...

I am able to change these values directly in smb.conf, but running testparm alone, i.e. using smb.conf as its default, still changes 'yes' to 'no'

SYSTEM:
/etc/samba:# uname -a
Linux desk2 2.6.32-36-generic #79-Ubuntu SMP Tue Nov 8 22:29:26 UTC 2011 i686 GNU/Linux

SAMBA VERSION: 2:3.4.7~dfsg-1ubuntu3.8

TESTPARM VERSION:
/etc/samba:# testparm --version
Version 3.4.7