Hi A few months ago I bought a MacBook Pro with OSX 10.8 and Parallels 8, installed a Windows 8 as guest and I had a lot of problems with the network connection. I've upgraded to Parallels 9, same problem. Upgraded to Mavericks, same problem. Upgraded to Win 8.1, same problem. I have some apps in the guest that needs to be connected to a database and when the network fails (a icon appears showing cable failure randomly) the apps crash. The host does not seems to have problems, in fact when the guest shows a network failure, the host can connect to the Lan and Internet without problems. The network is configured in bridge mode, I've reinstalled host, guest, parallels...no way, I'm getting crazy. Any hint?
This may or may not help, try going to the Parallels device menu and reselect the networking options while the VM is active (even though it still shows selected). I have an issue with lost network when waking from sleep and this re-establishes it. Perhaps your issue and the wake from sleep are related. Give it a shot and see what happens.