HP DV6 connects but no internet

I wanted to add this as a comment but for now I can't so I will just post it as an answer.

Here's what I will check for, the first is ifconfig, is the IP it gets on the same subnet as the gw. Is the subnet mask under the scope of the gateway.

check the /etc/network/interfaces file, does it look like

iface eth0 inet static
    address 192.168.0.200
    netmask 255.255.255.0
    network 192.168.0.0
    broadcast 192.168.0.255
    gateway 192.168.0.1 
#   dns-nameservers 192.168.0.1

I'll go for routes, any default route that use IP, and gw as default

try to ping from outside and see if it works.

try to connect other endpoints to access points do they work

try to connect that endpoint to another access point, does it work?

Such situation may happen for many reasons, e.g. if two computers with the identical MAC addresses are connected to the same subnetwork (like: when someone is using cloned MAC) - are there many computers on the same NAT (or is it public network)?
If you'd post output of ifconfig, it would be possible to cut out some of possible problems.

eth0      Link encap:Ethernet  HWaddr c8:0a:a9:0c:a7:45  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:41 Base address:0xe000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:561 errors:0 dropped:0 overruns:0 frame:0
          TX packets:561 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:42164 (42.1 KB)  TX bytes:42164 (42.1 KB)

wlan0     Link encap:Ethernet  HWaddr 00:26:c7:04:97:c0  
          inet addr:192.168.1.109  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::226:c7ff:fe04:97c0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:12 errors:0 dropped:0 overruns:0 frame:0
          TX packets:71 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:2035 (2.0 KB)  TX bytes:12371 (12.3 KB)

It seemed to be a network manager issue. As soon as I replaced network-manager with WICD the problem went away.