Hi everyone! I know the fix for this! I’m Brazilian, so i can't write right!
I had the same problem. My Samsung Galaxy Tab - (GT) P1000L - connected to WI-FI first and after that never connect.
What happen is that the GT first take an ip number (example: 192.168.1.102)
Than we turn off the router and turn on again and GT try to take the same ip address.
And you have a notebook and other things that connect to the router too. And they sometimes take the same ip that the GT is trying to take.
I have a TP-Link router WR642G. This can work with another TP-Link or other routers.
Enter in your browser (in a notebook that is connected to the router) 192.168.1.1 (sometimes is another number. the number is usually under the router, and the Username and Password too) if the password does not work, reset the router (push a clip on the hole) try again.
Turn off other things that are connected to the router.
Now we have to know which ip your GT took first.
Go to you GT and write down the MAC: example: 40:1F:E0:4R:Q3:7A (go to Wi-Fi configurations than click on Menu – Advanced)
(Menu is the first button below in the black border)
Now return to the router (browser in your PC)
Go to the DHCP Settings. Look the Start IP Address (mine is 192.168.1.100)
Go to DHCP – Address Reservation. – Add New.. In MAC Address input the number you see in GT, but input with this (-) example: 40-1F-E0-4R-Q3-7A
Now in “Reserves IP Address” input the IP you saw in DHCP Settings.
Try to connect your GT.
If don’t work, input the next IP, example (192.168.1.101) until it CONNECT!
I hope you enjoy!
the easy way is to restore fabric your GT.