Firefox woes

I'm not completely new to Linux, but ignorant enough that I can't troubleshoot something that'd be a snap in Winders. I've installed both Ubuntu 5.04 and 5.10 on a Toshiba laptop...I've confirmed that any and all of three network adapters (builtin Intel NIC, Farallon USB NIC, and a generic wireless PC card) I have attached are in fact working with ping, ifconfig, and all that.  I've successfully downloaded and installed all updates.  My shop network (DSL-based) is a simple one...permanent machines have static IP's, mostly Winders-based, with one OSX G4 Mac, and customer machines all hook up with DHCP without difficulty. Firefox, though, will not connect to any outside website...if I give it my web server's IP address, it'll load up my default page from it...I haven't tested this with any external IP addresses.  I'm assuming that DNS is working properly, since I can ping any URL successfully. It's as if Firefox isn't successfully using DNS, either with install 5.04 or 5.10 (DL'd and installed 5.10 after finding out it was available)...but if I explicitly define some DNS server IP addresses, it still won't work. I've had troubles with Firefox on Ubuntu installs before, when I was just horsing around with it...but it was just extremely slow rather than completely incapable of connecting.  I can only assume that I'm doing something wrong, since there don't seem to be anybody posting with similar problems.

...okay, I'm an idiot. Yes,

...okay, I'm an idiot. Yes, it was a DNS issue.  The list of DNS servers the DHCP from my DSL modem included the DSL modem itself...as soon as I eliminated "192.168.1.1" (the first entry) from the list, everything started working.

here is the solution

Open Mozila Firefox and type "about:config" in address bar and press Enter.
Scroll down to "network.dns.disableIPv6" and change its default value from false to true
restart Firefox and enjoy !