I have my Tattoo rooted with 1.6 (can't recall the ROM name) with build number 1.67.405.6. Almost everything works fine except the connection with my home WiFi network. It's a PPPoE connection through ADSL modem. Next in line is the Netgear WG602 v3 WiFi router. At the beginning I couldn't connect at all so I changed the router's ROM to DD-WRT. Now I can connect with the router but no connection to the internet whatsoever. I can ping my router through my Tattoo, I can even open the 192.168.1.1 and mess around with its software but no connection to the internet. It is only limited to my Tattoo as I can connect through my laptop, through my other mobile (HTC S710) and also I can connect my Tattoo with any other WiFi (Secured or Open) with no problems at all.

I tried with no Security, with WEP, with WPA-PSK to no avail. Any other clues?

(This is a crosspost with xda-developers as I'm very desperate to find a solution to this. As soon as I find it, I'll post the answer here also)

If you just flashed your router's firmware you need to go into the PPOE section and make sure you have the proper DSL settings. I no longer have DSL but when I bought a ZOOM ADSL router there were different types of connections. You may also need to enter a username/password for DSL to connect (I did for mine). Call your ISP when you have the DSL options screen up so they can tell you what info you need. Your phone can connect to your router but your router can't connect to internet.

Try a different WiFi channel on your router

The thing is that I can connect my laptop. I can also connect my other mobile phone to it. My Tattoo is the only one that cannot connect. I think it has to do with the pppoe as you said. But I didn't find anywhere any software for my android to create a pppoe connection on my mobile with my username and password.

Ok, if you're able to connect to the internet via your wireless router with your laptop and other phone we've pretty much narrowed the problem down to your tattoo.

I have 2.1 running on Galaxy S and there aren't really many options under wifi. Forget the advice about trying a different channel, that's not going to help. Make sure there is no proxy or port setup, leave it blank and under IP address make sure 'Use static IP' is unchecked, your router provides all this info (providing your router is setup for DHCP). Compare your phone settings with your laptop wifi settings.

I'm convinced it's your phone settings since you can connect to the router's default gateway, just not beyond that.

I tried with automatic IP and nothing. Then I tried with Static IP and still nothing. Under Static IP I used the same settings as my laptop. Same Gateway, Same DNS, Same IP range. my laptop is 192.168.1.7 and my mobile is 192.168.1.8

Anyways, I give up. I can't think of anything else. Thnx guys!