asterisk users - Sep 2011 - Grandstream HT 503, asterisk 1.8 and TLS

Hi,

I have a grandstream HT 503 ATA which seems to support TLS/SRTP. I
generated the keys and certificates for both the server and the device
as mentioned at
https://wiki.asterisk.org/wiki/display/AST/Secure+Calling+Tutorial

I then copied the grandstream.crt and grandstream.key over to the ATA.
Unfortunately, the device is refusing to register and in asterisk cli
i see

  SSL certificate ok
  == Problem setting up ssl connection: error:14094410:SSL
routines:SSL3_READ_BYTES:sslv3 alert handshake failure

Is there something which i am doing wrong?

Thanks
Rajil