Hey Jeff.
I have having issues similar to the OP but over network drives. We have a high powered video editing NAS (Isilon). Scratch disks are currently stored with the project on the network drive. Lately whenever we render a project, it sporadically disconnects us from the internet. Its extremely weird.
I can ping https://www.google.com and get replies constantly…and then render a project in Premiere CS6 and sometimes (sometimes it works) it disconnects me from our network completely. No pings. No websites. NO network drive. Nothing. I get an alert on my Mac that the share has been disconnected and the ping attempts time out.
At this point Premiere freezes at rendering a frame.
Most of the time if I just sit there, it will automatically reconnect and continue rendering where it left off with no problems. There is no specific time frame on when and if internet will be restored but restarting the computer always brings back the internet.
This isn’t happening on just one computer, but 4 of my Edit Suites .
If I point the scratch disks to the local desktop, the render works fine. However, there are times where different editors will edit different pieces of a project. We need that scratch disk to be locally available to all the editors.
Could you explain your issues with network drives and scratch disks?