Sorry, but I can't follow what you are doing - The suggestion was to test with another network card. But seems you still test with the old/internal card? (You told you will test a standard debian with proxmox kernel?)
I'll start from the top.
- I was having problems with bridging VLANs in PVE's web GUI to containers
- I tried creating VLANs inside the container.
- I installed CentOS and could create VLANs just fine.
- I installed Debian Lenny and VLANs worked just fine.
- I installed the PVE kernel and created the VLANs directly in the config files.
- The network card wasn't recognized, so this thread recommended a different network card.
- They still didn't work, so I did more digging and discovered that eth0 in Debian was now eth1 in PVE and the new network card was eth3, but because I hadn't configured eth1 or eth3 in ifconfig, they didn't initially show up.
- I believe VLANs were properly working on both interface cards, so I removed the Intel card.
- I had the VLAN pinging out, but further investigation showed the traffic coming out of the base interface as the host's IP instead of the container's IP.
- The container no longer can ping, but I didn't change anything.
Maybe it's because I'm the one that did everything, but I can track what I did in the previous messages I posted.