Teamviewer will not connect

[cuckman]

I have installed and running latest version ,my contacts can connect with me and view my pc but when i put their id in and click connect,it says" contact could not be established, no reason" great I have tried everything any ideas guys.would be very greatful for any help.

[ERS]

try typing in 12345 in the ID box and click connect, then use the password 6876. this should connect you to the TeamViewer "test" remote desktop.
That will confiorm that your side is working correctly.
Then...Have them restart their system.
Make sure that "full access" is checked in their options.
Make sure all ID's and passwords are correct.
Baring that trying reinstalling and getting new ID's

[cuckman]

thx yes have done all that but when i try and connect with a contact this comes up "A connection could not be established,reason unknown" any ideas this is with version 5 have scoured the web for any fix cant find anything,any help would be great!