Web Proxy / DNS Suffix Question

Hello - we are testing Mikrotik for use as a router between our wireless and wired LAN’s. Currently everything is working great except for one issue. I would appreciate any help that anyone might be able to give. Currently the MT box has a static IP on the LAN side and and points to our LAN DNS servers for DNS. MT is also setup as a DHCP / DNS server for our wireless clients. Clients receive an ip address and DNS suffix from the MT box. We are also running the caching web proxy. Our wireless clients have no problems browsing the internet - everything there is great. But our wireless clients cannot browse to any of our internal web servers on the LAN side without specifying the server name + suffix (webserver.xyz.net instead of just webserver). However our wireless clients can browse to these LAN webservers through Microsoft File and Print Sharing by specifying only the name without the suffix (\webserver\c$ for example) and we can do an nslookup from the wireless client and the address of the LAN web server is returned correctly, but for some reason the proxy will not resolve the name without the suffix. When we try to use Internet Explorer or Firefox to browse to webserver we get an error:

The requested URL could not be retrieved

The following error was encountered
Unable to determine Ip address from hostname for webserver

The dnsserver returned
Server Failure: The name server was unable to process this query

Also I just noticed that I cannot ping the webserver from the MT box itself without specifying the dns suffix. Is there a way to add a dns suffix search list into MT - maybe this would fix the problem?

Thanks for any help you can give