I have a 2010 Mac Pro that has a strange problem and I'm curious if anyone else has experienced it. I can't recreate it on the fly and it seems to be completely random (happening within 30 minutes of a cold start or after 10 hours of running): Without notice all network activity ceases to function, it's like someone pulled the network card. If I go into Network Preferences I still have a green line for the ethernet port (I'm not using wifi on this machine so it is disabled) and it shows an IP address (DHCP), etc. Unfortunately shortly after this happens (within seconds) I can't open up any new programs (i.e. terminal, activity monitor, etc). New programs try to open up but they fail to open, they just stay in the dock with no activity. If I try to close some programs (e.g. mail.app) those programs never close, I must do a force quit on them. After all running apps have been closed and I attempt to shut the system down properly it just hangs at which point I'm forced to hold down the power button to shut the system down. This happens the same way each time this problem occurs. I may go the entire day without an issue, but some days I may experience it two or three times so it's very frustrating. From day to day I have the same programs open all day so there's nothing new being brought into the mix that may cause the issue that I can see. Has anyone seen or experienced something similar? Ideas of how to resolve? Thanks!!