Hi thestrategist,
As from your sig. you own a 17" MacBook Pro and it support
802.11n, then why you stick with old Beetel modem, what I suggest you to go for Netgear N150 modem which extend your wireless range and also connection speed is improved using 'n' type wireless.
Also as suggested by
webgenius you can flash router firmware as you gain control over transmitted power of ADSL modem which in turn increase wifi range but don't expect dramatic change. Some custom firmware are
dd-wrt ,
Tomato and
Shibby mod.