I have a certificate from Apple, and I code sign my apps.
A few people have started reporting ‘non identified developer’ messages in Mavericks.
Isn’t code signing enough now?
Whats an identified developer, if not one that is paying Apple ?
Check out conversations with “–deep” here on the forum. For instance my own at . Got that working, by the way, for Xojo, and need to revisit for RS2011r4.
Can’t edit my post. The correct link is https://forum.xojo.com/6192-no-identity-found-when-codesigning
Summary:
With Mavericks, Apple changed their code signing & code signature validation and this mainly affects Xojo (but does also affect other development tools including Xcode), it affects apps that include ‘nested’ code or additional executable code that is separated from the main executable file.
The long and the short is that code signing the application bundle and main executable is no longer enough, Xojo uses Dynamic Libraries and these must now not only be code signed, but the code signature must be the same the as bundle code signature.
And that’s fixed by using the --deep parameter?
If you’re manually code signing then adding the --deep and the -f option is your easiest solution. If you’re using a third party tool like App Wrapper or App Wrapper Mini, I’ve posted a support document that will help there.
http://www.ohanaware.com/support/mavericksCodesign.php
Thanks all. I can only mark one as ‘answered’, but all responses helpful.
Well one thing is positive. It makes patching code signed apps a bit more difficult. 
This was giving me a hard time for a few days. I found this article helpful: