10 minute browser timeout

I'd appreciate some help with the following problem:
I have an ASP.NET 1.1 application running on IIS 6.0. My page
executes a SQL script (Oracle) and displays the results on the page.
One particular query takes a long time to run (>20 minutes). After 10
minutes, the browser "gives up" and displays the timeout error (tested
on both IE7 and FireFox). I'm looking for something that will allow
me to let the client's browser run for more than 10 minutes, without
giving up.

We have run this from a different server, and there is no timeout -
the client's browser continues to run, and there is no timeout. The
only differences we can see are that the 1st server is on SSL while
the 2nd is not, and the 1st server is Server 2003 32 bit, while the
2nd is Server 2003 64 bit. We are not able to easily test either of
these issues. (There is also no timeout when it's run on my local
desktop, on XPSP2 and IIS 5.1).

We have determined that the query is optimized - it's a complex query
that hits some huge tables, so it really does take 20+ minutes.

We are not able to rework the page logic at this time - long term we'd
like some kind of asynchronous query where the results can be
requested, then later retrieved, but that's not available at this
time.

IIS connection timeout is set at 1400 seconds (about 23 minutes).
The .NET application is set to timeout after 15 hours (httpRuntime
executionTimeout), so I know that's not at issue. I've used the same
application, web.config and machine.config on both servers, and
checked with .NET specialists, so I'm reasonably sure that it's not
a .NET issue (although I'd gladly accept any advice relating to that).

I'd appreciate any insight into what controls the client brower's
timeout time. There must be something on the server.

Thanks for your help.

Joe Enos
joe@jtenos.com