WNDR3800 in combination with a Samsung Tablet - unstable ping results

Hello,

I have a strange issue with the Netgear router in combination with a Samsung Galaxy Tab 7.0 (GT-P6210).
After a slow browsing-experience on the tablet I decided to investigate the problem. The connection with the router itself is ok, (it can fall-back to another Wifi-Access point, so only 2 in it's memory, but it doesn't, it stays connected to the WNDR3800).
From any other device (connected by cable or Wifi) if I do a ping to the device, I get very poor results:

...
Request timed out.
Request timed out.
Request timed out.
Reply from 192.168.1.3: bytes=32 time=862ms TTL=64
Reply from 192.168.1.3: bytes=32 time=3ms TTL=64
Request timed out.
Request timed out.
Request timed out.
Reply from 192.168.1.3: bytes=32 time=60ms TTL=64
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Reply from 192.168.1.3: bytes=32 time=2ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2ms TTL=64
Reply from 192.168.1.3: bytes=32 time=479ms TTL=64
Reply from 192.168.1.3: bytes=32 time=1348ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2ms TTL=64
Reply from 192.168.1.3: bytes=32 time=624ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2900ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2ms TTL=64
Reply from 192.168.1.3: bytes=32 time=531ms TTL=64
Reply from 192.168.1.3: bytes=32 time=1297ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2525ms TTL=64
Reply from 192.168.1.3: bytes=32 time=1ms TTL=64
Request timed out.
Reply from 192.168.1.3: bytes=32 time=1148ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2478ms TTL=64
Reply from 192.168.1.3: bytes=32 time=2ms TTL=64
Request timed out.
Request timed out.
Request timed out.
...

The tablet is on its original Android 3.2 (no updates available for the moment), it's just out of the box, nothing special installed. Wifi is always on, no sleep enabled.
Symptoms are the same with different router settings:
(The firmware version is V1.0.0.32)
- on 2.4GHz, 5 GHz, 300/150/54Mbps,
- different channels (there are even no other 5GHz-band channels active here)
- with or without Wireless Security settings (WPA2)
- RIP on or off
- DHCP on or off
- ..

When browsing with the tablet, the ping's are mostly passing through but not stable either, it's like the browser is asking for activating the network card..

Other devices (tested with Archos 7.0 internet tablet, laptops, smartphones, ..) are working fine (maybe problems with a Toshiba Folio too..) and even very well with multiple unicast streams at 12 devices simultaneously.. (was not possible with the WNDR3700)
Where pings are constant at 2-8ms.

If I use another brand of router the tablet has no problems (even when no internet connectivity app is open) and no "Request time out"-pings are present.


Do you have any idea what I can try, or is the WNDR3800 just not working with this tablet very well?
Has anybody else these same experiences, or with other tablets (Samsung Galaxy series or other brands?)

Thanks in advance!

Aaron