How to connect laptop to HDTV and have a cool monitor

Hi - -this is a question of which many answers seem to exist on the web, yet I haven't been able to make it work.

I have a 32" sony bravia lcd hdtv, and an IBM T41 (XP SP2 and latest Lenovo driver updates)with a DVI output on the docking station. I bought a DVI to HDMI cable and thought that if just changed the resolution to 1280x1024 on the external monitor that I could use this wonderful tv with my wireless keyboard as a cool livingroom surfing option.

However, when I do the normal things that I would do for an external monitor or projector, I get no image. Booting from the pc only gives me a "black" lcd screen and nothing on the TV.

Now, I once, accidentally got it to work and had part of my windowsdesktop in an 640x480 resolution on the TV, so I know that it isnt a connection issue.

The main problem seems to be in the settings -- does anyone have some experience or suggestions ? Especially with the Sony 32" and the IBM T41 Docking or similar HDTV/LCD to XP laptop/docking ?

Thanks

Marc