I am another user that is trying to sign JAR files using jarsigner, and am running into the same problem as is decribed above by other users. I believe that the post by the user who suggests that the Authenticode protocol is different than the standard protocol is correct. Please respond and let us know if Comodo has a URL that supports the timestamping protocol used by jarsigner and, if so, where we can access it. If Comodo does not yet support this, we need to know when you will.
For the record, the error message I'm receiving is:
"jarsigner: unable to sign jar: java.io.IOException: MIME Content-Type is not application/timestamp-reply"
If you (the Comodo support team) need more information on jarsigner and its support for timestamping, please see:
http://java.sun.com/j2se/1.5.0/docs/guide/security/time-of-signing.html