I got very different timings from script accessing gdata (Google servers) on Windows and Ubuntu on same machine and thought to compare ping google.com results:

x-axis: packets
y-axis: ms
Ping statistics for Windows 7:
Packets: Sent = 100, Received = 100, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 54ms, Maximum = 107ms, Average = 57ms
--- google.com ping statistics Ubuntu 11.04 ---
100 packets transmitted, 99 received, +4 duplicates, 1% packet loss, time 107550ms
rtt min/avg/max/mdev = 49.688/451.811/2436.608/532.491 ms, pipe 3
What could couse this lag?
I suspect that it's latest kernel update which was yesterday (2.6.38-12-generic), as I think everything was fine before last update, but I'm not sure
Also, please feel free to ask for data, as I'm relatively new Linux user, and Linux network is foreign to me
edit 1: Here is output from iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
wlan0 IEEE 802.11bg ESSID:"home"
Mode:Managed Frequency:2.412 GHz Access Point: 00:1F:9F:71:82:AF
Bit Rate=48 Mb/s Tx-Power=27 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=39/100 Signal level=39/100
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:383 Invalid misc:93 Missed beacon:0
syslogand this log line:kernel: handle_rx_packet: invalid, small RX packet : 1seems like it's repeating from when this issue started. – zetah Oct 29 '11 at 18:04