just thought i'd drop a note to say i'm having a very similar problem getting twinview to work on my geforce fx5200. i only installed suse linux for the first time last weekend, and though im enjoying the linux experience so far, this twinview problems is really getting my goat.
im using an ag neovo lcd display, and trying to run my tv off as the second monitor, for playing games and dvds and what have you. however, when i edit my xorg.conf file, and add the "connectedmonitor" option as "tv, dfp" or "dfp, tv", my flat panel refuses to work. i'm getting output on the tv, but no amount of editing or messing around can seem to get my flat panel to work at the same time :@
if anyone has any ideas, do please tell. i'm dying to watch a dvd and the small screen just isnt enough!