Hrm well..this is just my attempt at getting this little detail looked at for all owners of notebooks with widescreen resolutions :

The hardware :

Inspiron 8600 w GeForce FX 5650 Go

Well to begin, in all Quake 3 engine powered games it's possible to specify a custom resolution in game through the use of certain cvars :

r_customheight
r_customwidth
r_mode (set to -1 to use custom resolution)

The Inspiron 8600 that I own has a 1680x1050 panel (sort of an oddball resolution).  By modifying those 3 cvars in the game's cfg files you could specify a custom resolution for JKA.  

I've done this already in single player, and with an added adjustment to the fov (cg_fov) I wound up with an awesome looking widescreen JKA with a wide field of view (you have to see it to in person to truely appreciate it).

Now the problem is : this little adjust does not seem to work in the multi-player game.  And I'm fairly certain this is a bug and not by design as well (unless it's a bug put in by design).

To get this to work in the MP game, you'll have to do this through the console AFTER the match has started already.

I.E. start the game with 1280x1024 resolution, get in the game first (match starting, or where you can physically see your character on screen), and then change the resolution in console through r_mode "-1" and a vid_restart.  

At least one particular screen in JKA crashes the game if you use a custom resolution with it.   As near as I can tell the screen that's currently causing this problem is the overlay of the face/model selection and saber selection menu that's laid on top of the game running in the background.

Raven would be doing all of us who own widescreens (desktops and laptops) a HUGE favor if they could fix this little issue with the next patch.

'k I got a bit wordy there :

The cliffnotes version of that post :

Some overlay menus in the multiplayer game does NOT like custom resolutions.

I'll need to verify again later tonight which screens are crashing the game.  But something is preventing JKA from launching in MP in widescreen mode.

Okay the JAMP executable crashes if you try to get into a game while under widescreen mode.   Something to do with the transition from the starting game menu to the actual game screen causes a crash while under r_mode -1

This crash bug isn't isolated to notebooks :

I just reproduced it on a desktop (GeForce FX 5900 Ultra + 45.23 WHQL drivers):

to repeat - this will cause JKA to crash every time on Multi Player - but it works great in single player

Set a custom resolution in the command line that's supported by the drivers (in this case for the desktop it was 1280x720)

r_customheight 720
r_customwidth 1280

setting r_mode -1 in the cfg file will let you start up JKA multiplayer in widescreen 1280x720 mode.  

Now start a game, and watch JKA crash in the middle of loading a match.

The curious thing is if you start the game with 1280x1024

r_mode 8

and *then* change your in-game resolution to 1280x720

r_mode -1 at the console while in game.

you will not crash, and still be able to play the game in widescreen mode.