1360x768 resolution - Kubuntu gets it, how about Lenny?

[lugoteehalt]

Dunno if this right place to ask, but I can get Kubuntu to give 1360 x 768 resolution, the native resolution of the LCD TV I'm using as a monitor.

I cannot however get Debian Lenny, my main system, to use it. Any chance of transfering Kubuntu's X server to Lenny or whatever? Any suggestions gratefully recieved. Anything special about Kubuntu's X? This must be an enormously common problem.