I am having this problem too >.<
I just bought it(RT-N12HP B1) few days back and my lappy always got disconnected from the wifi for few seconds and it connect automatically again.

Is there any settings that I configure wrongly? I am new to these things and the shop didn't help me configure.   

Please help.

I have checked the System log and this shows in the "General Log" after I have disconnected and connect back
Jul 22 10:42:13 pppd[264]: Serial link appears to be disconnected.
Jul 22 10:42:15 WAN Connection: Fail to connect with some issues.
Jul 22 10:42:15 stop_nat_rules: apply the redirect_rules!
Jul 22 10:42:19 pppd[264]: Connection terminated.
Jul 22 10:42:19 pppd[264]: Modem hangup
Jul 22 10:42:29 pppd[264]: Connected to 00:00:5e:00:01:0d via interface vlan500
Jul 22 10:42:29 pppd[264]: Connect: ppp0 <--> vlan500
Jul 22 10:42:32 pppd[264]: PAP authentication succeeded
Jul 22 10:42:32 pppd[264]: peer from calling number 00:00:5E:00:01:0D authorized
Besides that, I have doubt about the latest firmware for RT-N12HP B1
http://support.asus.com/Download.aspx?SLan...m=RT-N12HP&os=8
- 3.0.0.4.378.6117
http://www.asus.com/Networking/RTN12HP_B1/HelpDesk_download/
- 3.0.0.4.376.4018

Which 1 should I use?