Resolved by installing a VLAN capable network card in the client machine.  Apparently PowerConnects no longer handle multiple untagged VLANs in 3.x firmware.  Worked just fine in 2.x firmware.
We're currently running a stack of PowerConnect 6248P's with firmware 2.2.0.3.  I followed the upgrade procedure for upgrading the firmware and boot code to 3.2.0.7 (the latest available) and all seemed well until I did some checking on the status of one of our computers that talks to two VLANs we have setup: The phones continue to work fine, the entire voice network seems to work fine even, but when I checked out the attendant console I noticed something weird.  The attendant console software could no longer communicate properly with the VOIP server.  I could ping back and forth between the two VLANs just fine, no packet loss, but some data was obviously being lost as all of the phones appeared to be offline according to the attendant console software.  The phone attached to the same connection (tagged as 10) still worked flawlessly however. If I revert the firmware and configuration file to back to 2.2.0.3 everything starts working properly again. Here's my setup for VLANs: This setup works flawlessly with firmware 2.2.0.3, but when upgrading to firmware 3.2.0.7 it seems to break this. After upgrading to 3.2.0.7, the VLAN Membership screen changes and all of those blank entries now change to F (Forbidden) for the current status.  If I try to make any changes and apply them I get the error: error! default vlan cannot be made static At this point I'm lost on how to proceed.  Things are running just fine with 2.2.0.3, but I would prefer to be on the latest recommended firmware, particularly if we end up having to add switches in the future and those switches come loaded with the new firmware.  This really can't be as complicated as it seems can it? One issue is that our attendant console is obviously required for business and I can't do anything with the switches until after hours.
PowerConnect 6248P VLAN issue after upgrading to 3.2.0.7