I used to have issues with ident but for someone reason using a ident server and disabling inbuilt flash/mirc ones worked for me.
First of all make sure in mIRC it only listens for ident on connect, otherwise it will be blocking the port.
If it is set up correctly, grab this and try it:
http://www.tinyirc.net/identd.shtml.
If it fails to start correctly in the status window you have something blocking port 113 on your machine and the problems explained. If it starts OK the problems fixed
