Just a question, was the other router that you tried one in your house as well? maybe you want to try another one elsewhere, or try a factory reset of your wireless router at home.
I have followed your suggestion about reflash the Radio. Unfortunately, it doesn't work.
Besides, I messed up when I flashed the radio. The radio does flashed into WinMo as it should, but my WinMo was also like have been hard reset. And no I did not flash a Rom, no doubt about this. I just took a quick radio flash. So that means even my WinMo is hard reset, the Wifi problem is still there in Android. Can connect, but no connectivity to outside.
I will leave this problem from now. It was fun and pleasure to try FRX and GBX. Excellent works. But as Arrrghhh said, nand is future. At least for me. The only reason I keep my WinMo is I have TomTom on it, but from now I will like to try Android on NAND on my TP2.
However, Thank you for the suggestion. For me it does make sense as you say, that the problem shall be Rom/Radio related.