I didn't mean for you to delete the entire servers.ini file, but in reference to your query, in mIRC type the following command (it doesn't matter if you're connected or not)
//echo -a $readini(mirc.ini,text,defport)
That will return the default connection port as stored in mirc.ini
It would not surprise me to find that your default setting has been changed to 6697, so that is what all connections will try to connect with.
Let me know what results you get so that I can investigate corrective action properly.