Singtel MIO Broadband and Problems with Macbook.

I have never had problems with my wireless/airport connections. But recently my brother signed up for Singtel's MIO, and that was when the nightmare began.
Everytime i'm online, the wireless connection goes off every 2-3 minutes. The MIO is on WEP password protection btw. I have been trawling forums online and have tried some solutions, but nothing seems to work. Someone suggested going to console. app and tracking the problem down. and each time the connection dropped, the console would display this:

12/14/08 11:40:27 AM [0x0-0x11011].com.apple.Safari[101] Unsafe JavaScript attempt to access frame with URL http://85.17.212.147/a.php?c=728x90 from fram

so someone suggested to disable the automatic detection of ivp6 (or something), and it worked for 15 mins, after which the connection would drop and i saw these messages:

12/14/08 11:41:49 AM kernel AirPort: Link Up on en1
12/14/08 11:43:40 AM kernel AirPort: Link Up on en1
12/14/08 11:45:48 AM kernel AirPort: Link Up on en1
12/14/08 11:49:52 AM kernel AirPort: Link Up on en1
12/14/08 11:51:30 AM kernel AirPort: Link Up on en1
12/14/08 11:54:40 AM kernel AirPort: Link Up on en1
12/14/08 11:58:59 AM kernel AirPort: Link Up on en1
12/14/08 12:01:29 PM kernel AirPort: Link Up on en1
12/14/08 12:01:39 PM SCHelper[281] no command
12/14/08 12:01:39 PM com.apple.launchd[70] ([0x0-0x21021].com.apple.systempreferences[276]) Stray process with PGID equal to this dead job: PID 281 PPID 1 SCHelper
12/14/08 12:06:13 PM com.apple.launchd[70] (0x10c6e0.System Preferenc[314]) Failed to add kevent for PID 314. Will unload at MIG return
12/14/08 12:07:32 PM kernel AirPort: Link Up on en1
12/14/08 12:12:15 PM kernel AirPort: Link Up on en1

FYI, i need to clarify 2 things:
1) i know that it can't be my wireless card or something as i live elsewhere over the weekdays and do not have such problems. the problem only occurs when i'm at this house over the weekends and use Mio
2) i know its also not the MIO as my brothers (non-MAC users) do not have this problem on their laptops. The MIO is btw connected to a PC, and we have two other non-mac laptops and my MAC tapping onto the wireless.

I called singtel but they told me to solve it myself as its a MAC problem (?!)

maybe it's my setting somewhere? something is wrong with the firewall!? i have to clarify though that each time the connection goes off, it goes on back immediately when i manually select it at the airport list of connections

I really appreciate any form of help, really, and please make your instructions as clear as possible as i'm rather tech-challenged.

ALSO, mother of all surprises, the 10 mins that i;ve taken to type this out...the connection hasn't dropped at all.

pls help!