xf86-video-mga-1.6.1 vs. 1.4.11 re: 1600x1200

[Winston]

Summary: I haven't been able to get 1.4.11 to do 1600x1200.  Would 1.6.1
	 do any better (if I could get it to build)?

Details:

* [FreeBSD 9.0-RELEASE has xf86-video-mga-1.4.11 and Xserver 1.7.7.]

* The specs for the Matrox MGA G200eW Nuvotron chip say that the chip
  supports both 1600x1200 and 1680x1050 at 16-bit depth.

* I'm currently running 1600x1200 x16 using the VESA driver, proving
  that my monitor, the G200eW, BIOS, X server, etc. support that
  resolution.  For various reasons, though, I'd like to be able to use
  the MGA driver.

* When I change xorg.conf from Driver "vesa" to "mga", despite trying
  many other things including use of detailed ModeLines in various
  places, the 1.4.11 MGA driver rejects both 1600x1200 and 1680x1050,
  with (IIRC) "no such mode".

I didn't see anything in 1.6.1's Changelog specifically about fixing a
>1280x1024 problem, but there was a change re: recognizing 16MB instead
of 8MB in some cases.  My log file said the mga driver saw 16MB, though,
so I don't know if the fix applies to my chip.

I downloaded xf86-video-mga-1.6.1, but the build failed when
./src/mga_dripriv.h tried to #include "GL/glxint.h".  (The directory
and several other GL/*.h files exist, but not that particular file, and
grep __GLXvisualConfig in the files under GL/ found no matches.)

So, I'm left with having to ask whether 1.6.1 would help or not, and if
the answer is yes, how do I get past the GL/glxint.h not found problem?

Thanks in advance!
 -WBE