Hmmm , had this problem with 2.6 server... Maybe you can check for the following things:
Maps in Client and Mir Server... if they are .rar unrar them and should work lol
If not , sorry can't give u another answer=]
Edit:
Double check the ip's in the ini's
Also did u forward ports?
Also :
Check that is 0.0.0.0 ...
Everything found by searching =]