Ubuntu network Troubles

I have just installed Hardy on my machine (For the third time) and get the same error each time i change network settings!!! The steps i take to screw up my installation are as follows: I go to System>Administration>Network>Select unlock and enter password>I select the General tab>Under host setting i change my Domain name to "Tonk" (from nothing)> select closethis causes a few highly annoying errors! My repository stops working as soon as it goes online to download an app or update the lists, and my gnome partition editor doesn't open anymore (The system monitor reveals that there are processes running for these apps but no GUI comes up). I am on an ordinary windows network. This has happened before its only now i have been able to isolate what causes the errors. To rectify the problem i have reformatted. Whats the underlying causeto this problem? I don't want to go back to windows! please help

Ubuntu network Troubles

My laptop worked perfectly until I recreated this problem. Unless you have a very good reason for changing the Domain Name then quite simply - DON'T!!! Just leave it blank.