As at 191.06 it appears that 5040 and DX10 is enabled, just install the driver, latest GXM and firmware from Matrox and run the Wizard. YAAAYYYY!!!! Note The latest ATi drivers also appwear to allow 5040 :)
If you are trying to get 5040 res with 177.92 or latter NVidia driver (ATi cards can't do 5040 res, sorry) your monitors might give you an 'out of range' (or similar) error. This is often not a fault of your monitor but a driver/PowerdeskSE/GXM problem. You can try either of the 2 options below:
OPTION ONE: Try this unofficial GXM if you have a 200 series card: I have an UNOFFICIAL BETA version of the PowerDesk-SE software which fixes the 'out of range' error and works under Vista and Win7. However this only works for 200 series cards (GTX260, 280, 285 and 295). Try at your own risk, get it from
this thread.
Note: There has been some success using this GXM with cards other than 200 series, i.e. 8800GTX. Give it a whirl!
OPTION TWO: if you don't have 200 series card try a custom resolution: (and see note above) according to Mattsimis
here (and tidied up repost
here) you can set 5040 up as a custom res in up-to 180.48 and latter drivers. Give it a go :)
READ OTHER THREADS: Some people have figured other ways but the 2 above are the main, and most successful, ones :)
This is the official thread but we have figured out that many of the problems are with the latest NV drivers (latter than 177.92) and Vista...install XP it works fine with the latest drivers ;)