ofcourse mashimus,
I guess some screenshots are the way forward:
http://wl500g.info/showpost.php?p=119830&postcount=4
as you obviously have seen it's inside the web admin from your router
the first screenshot is of the settings in: wireless -> interface
the 2 last screenshots are from: wireless -> advanced
In the first screenshot it's importand to set the bandwith right.
40MHz is for a router with a few wireless clients, and made for maximum troughput.
20MHz is for a router with a lot (30 or something) of wireless clients, but is overall a bit slower if you have just 1 client connected.
on the second screenshot you see "Enable afterburner" on the top (should be on yes)
"Regulatory mode" = 108.11h (no 108.11d, it will give you slow speeds, use the H viariant!)
on the thirth page: frame bursting (gives usually a lower ping), and wmm is for wireless clients with batteries, like a mobile phone with wifi. Laptops usually don't support it and it's made for low power usuage
you all find it?