An interesting observation

[Steve Snyder]

On Monday 04 February 2008 10:06:36 am Craig White wrote:
> On Mon, 2008-02-04 at 06:56 -0800, Leslie Satenstein wrote:
[snip]
> >
> > Yesterday, I bypassed the router, and noted a marked improvement in
> > response times.  Is it subjective? Firefox appears to works better,
> > with what appears to be faster responses. I also noted that Firefox
> > did not lose responses. (I had the problem with the router in place
> > that Firefox would hang, waiting for a return response. To get that
> > final or missing response, I had to click on the refresh button. Now,
> > it does not seem to hang).
>
> ----
> Try disabling ipv6 the next time you insert the router in between. If
> you don't have ipv6 DNS resolution, it can slow things up considerably.

It's long been reported that Firefox/SeaMonkey do not like IPv6 in Linux.  
It's a common optimization to disable it:

	user_pref("network.dns.disableIPv6", true);

The OP may very well have a generalized networking problem, but if the 
symptoms (delays) are only seen in Firefox, the above may fix it.