Why does the subject refer to a "Netgear Wireless Router" but the body refer to a d-link?
In any case, I've had a Netgear wireless router in my home. When I got my iMac, I had great reception but very slow web page loads. Turns out that DNS information was not getting transferred to the Mac. I had to manually plug in the DNS server names into the TCP/IP tab in the Networking Preferences.
However, this does not solve your problem since you cannot tell your hotel clients to update your their DNS servers.
Have you considered switching out the d-links with an Airport Extreme + Airport Express. I have used this combo in our office and it worked for both our PC and Mac users.
Eventually, we got tired of the dead spaces and replaced all the consumer wifi equipment with a
Cisco Aironet 1130AG for about $500. Much better coverage and absolutely no complaints from anybody since.