Two ideas:

in www2sms.py change the first line from

#!/usr/bin/env python
to
#!/usr/bin/python

if this does not help, try do edit the desktopfile (/usr/share/applications/hildon/www2sms.desktop) from:
Exec=/opt/www2sms/www2sms.py
to
Exec=/usr/bin/python /opt/www2sms/www2sms.py
or
Exec=python /opt/www2sms/www2sms.py


But I am not shure about that ;-)

Thanks for testing, I appreciate it very much!

Cheers
Bjoern