[Zope] htmldoc problem

[Garry Saddington]

I am using the following external method to write pdf files.

import  subprocess
def html2pdf(self,source):
    f=open('/opt/scholarpack/ancillary/pdf.html','w')
    f.write(source) 
    f.close 
p=subprocess.Popen(['htmldoc', '--webpage', '/opt/scholarpack/ancillary/pdf.html','-f', '/opt/scholarpack/ancillary/mypdf.pdf'])
    p.wait()

When I do this the html is truncated and an incomplete pdf is generated. 
However, if I rum htmldoc in a terminal on the same html file then the ouput 
is perfect. Can anyone see where the external method may be going wrong, 
apart from the formatting that kmail is enforcing on this code snippet!?
Regards
Garry