IBM Thinkpad T41
* Intel Pentium M 1.6GHz Processor
* 256MB PC2700 DDR Memory (2GB Maximum)
* 40GB 5,400rpm Hard Drive
* Modular 24x CD-RW Combo Drive
* 14.1" XGA Display and
ATI Radeon 9000 Graphics with 32MB of Dedicated Memory * SoundMAX AC'97 Audio
* v.92 56Kbps Modem, 10/100/1000 Ethernet and 802.11b Wireless
* Two USB 2.0 Ports and One Type II PC Card Slot
* 12.2" x 10" x 1" @ 5 lbs.
* Windows XP Professional and Access IBM Productivity Software
this is all that matters.
Looks like you need to go to here:
http://support.amd.com/us/gpudownload/Pages/index.aspxand select the appropriate operating sytem and package for your setup.
This should give you a control panel for your graphics card that will probably let you select this resolution or add custom modes.