Slow local resources over WiFi?

Question

IIS

There is an access point ZyXEL P-600. There is a local network with a gateway server (Win2003, Lan2Net - NAT firewall and IIS - local corporate site).
Mobile staff have a number of laptops. On all laptops, except for one, WinXP is installed, one computer is Vista. But WiFi flies on all laptops - the network works fine, the Internet and the local site work with a bang. On a laptop with Vista, local and external Internet also work fine, but when accessing the local site, there are significant delays (about 20-30 seconds to open each page).
I rummaged through the net - I did not find anything sensible. What could be the problem?...

Answer 1

The problem was solved by using other settings on laptops with Windows Vista and Windows 7, in particular "WPA-PSK + TKIP", while using "WPA2-PSK + AES" on the access point itself and on laptops with Windows XP. Now everything works smartly for everything, both the external Internet and local resources.

Answer 2

Check the DNS settings on the Vista machine.

Answer 3

did you look with wireshark? that when both bags run. First of all, we look at the DNS that it arrives as sent, then http.
In general, initially in the hosts, try to register the correspondence to the local domain ip address and go to this domain on the local server.