Sarika,
If you are using SMP 3.0 SP03 on the server then you need to be using an Agentry 7.0.3.x client. You should not be using anything from Agentry 6.1.
With SMP 3.0 we don't use the .pfx anymore and instead use the certificate from the SMP 3.0 server. Check the link Steve mentioned for more details.
--Bill