I've just connected to my office network for the first time since upgrading to leopard, and what a nightmare. Everything crashes. Safari, Skype, Adium, Dashboard. I keep getting popups for me to sign my widgets into keychain with my network password, only to be told my username and password are wrong. Safari opens for a few seconds then unexpectadly quits, the same with skype and adium. I can't send a report to apple. If I pull the ethernet cable out Safari will open with the no connection message, but stay open, as will skype and adium. And my widgets will sort themselves out in dashboard. All my settings are untouched. My colleagues tiger machine still works OK. Everything is OK using my home dial-up connection, and no problems at my parents house with their DSL connection shar4ed via airport from their iMac. The office network connection has let me update some apps, lastfm is one that definitely worked. What could possibly be happening?