kmail & digital signature

Hi,
I have obtained digital signature recently. I am able to use the same
without any problem in evolution. But kmail does not sign s/mime saying
'general error'. I have all the required certificates installed in
kleopatra and kmail has imported my digital certificate in
tools>certificate_manager. I have selected my digital cerificate in
kmail>settings>configure_kmail>Manage_Identities.
Has any one been successful in using digital certificates in kmail? Am
I missing something or is there any bug or feature missing in kmail.
Thanks in advance.
Rajesh

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