I have the same problem. I ordered a 56 POZ jersey from seller "right20" and the Tracking Number I got doesn't work either.
However, that is not the strange part. The day before (maybe 2 days before) I got the Tracking Number, I contacted the seller about the status of my jersey. He had written me to confirm the size I needed. He told me the next day that the size I needed was not available and it would be a bit before the manufacturer could make one because they were busy making Favre and Vick jerseys. Well, I told him if it was more than a few days, I would have to cancel my order and get it somewhere else. He told me he would keep me posted.
Anyway, the next day (maybe 2 days later) I received a Tracking Number saying that my order had shipped! Well, that seemed strange to me after just talking to the seller about how it was going to be delayed. I asked the seller about it and he told me he would look into it, but I haven't heard anything in 2 days.
The tracking number still doesn't work in any system and I am kind of stuck in limbo here waiting for something to happen. I logged into DHgate and it says my order shipped on 8/26. So, I guess I am just going to have to wait until the end of next week to see what happens. It will probably take about a week to get here based on what others have said, so I am willing to stick it out.
But yeah, my Tracking Number does not show up in any system either. Not sure what is going on.