Multiple X servers?

[Richard Cobbe <rcc@inet.com>]

Greetings, all.

I'm running a stock Potato r3, and I'm having some difficulty getting X to
cooperate.  My computer uses the Intel i810 chipset on its video hardware,
and I've downloaded the necessary modules and X server from Intel, and in
general, things are working fine.

Intel's X server for this chipset does not currently support 32bpp, so I'm
running at 24.  This makes a number of applications slightly cranky: some
of Netscape's icons don't display correctly, and acroread either crashes or
displays the document incorrectly.  (I've attempted to run acroread
remotely, off a RedHat 6.2 box, and it exhibited the same behavior, so I'm
pretty sure it's the display.)

I don't want to run 16bpp on a regular basis, because my monitor doesn't
handle that particular video mode as well---it displays, but it's not as
crisp as 24/32 bpp modes.

I'd like to run two X servers on this machine: one in 24bpp on vt7, for my
normal stuff, and one in 16bpp mode on vt8 for those apps which can't
handle 24bpp mode.  (I'm not running [xgk]dm or any of the other display
managers.)  I've done this previously under RH6.2, so I know this is
possible in theory.

So.  As a normal user, I tried `startx -- -bpp 24 :0', and this worked
fine.  After this, I switched back to a text console and did 
`startx -- -bpp 16 :1'.  This brought up an X server on vt8, but all of the
clients started in my .xsession appeared on display :0, not display :1.
Since FVWM refuses to run on display twice, this second server terminates
as soon as it gets through the interactive bits of my .xsession.

What am I missing?  How can I get these clients to use the correct display?

Thanks,

Richard