I was able to connect fine via samba (SMB) to my networked servers during the week but starting on Friday this kept happening to me. I know that the connection to the server is fine as it works PERFECTLY on my Windows 7 Ultimate backup PC. I've tried all the diagnostics that I could (PRAM, PMU, Apple Hardware Test, Reinstall.etc) and came up with no luck. I even spent an hour on the phone with Apple Technical Support but they never heard of this problem and weren't able to help over the phone. I made a quick video explaining what is happening and uploaded it to youtube for demonstration purposes. http://www.youtube.com/watch?v=ipcNpDE0EhI The computer is a 27" Core i3 iMac w/ 4Gbs of RAM and an ATI Radeon HD 5670. Any ideas?