Infrastructure Software

I've got hotdesking working on RedHat Linux 5.4 with SRSS 4.2EA1. The problem is that the monitors connected to the SunRays have different resolutions. When I pull out the card and put it into another unit, I'm getting the session, but at the resolution of the monitor used for logging in.

I tried to set the proper solution with xrandr, but that only allows me to select modes and it doesn't show any widescreen modes, except the mode used when logging on. e.g.
[root@raven pam.d]# xrandr
SZ: Pixels Physical Refresh
0 640 x 480 ( 452mm x 254mm ) 0
1 800 x 600 ( 452mm x 254mm ) 0
2 1024 x 768 ( 452mm x 254mm ) 0
3 1152 x 900 ( 452mm x 254mm ) 0
4 1280 x 1024 ( 452mm x 254mm ) 0
5 1280 x 800 ( 452mm x 254mm ) 0
6 1400 x 1050 ( 452mm x 254mm ) 0
7 1440 x 900 ( 452mm x 254mm ) 0
8 1600 x 1024 ( 452mm x 254mm ) 0
9 1600 x 1200 ( 452mm x 254mm ) 0
*10 1600 x 900 ( 452mm x 254mm ) *0
Current rotation - normal
Current reflection - none
Rotations possible - normal left inverted right
Reflections possible - none

This was run on a SunRay with a 1680x1050 monitor connected. The session was started on a unit with a 1600x900 monitor connected. I can select any of the other modes just fine (xrandr is enabled with utxconfig), but I cannot set the resolution I want.