Hi,
It might not be the driver itself. In the configuration file /etc/X11/xorg.conf there are settings to tell the computer what resolution ti display on the monitor, and at what frequency. It is most likely that your computer is putting out a signal that the TV canoot dsiplay.
TVs (plasmas and LCDs ) are especially fussy when it comes to the resolution and frequency.
You have some things you can do:
1) Check the net for a "modeline" for your TV
2) Create your own modeline using a Windows laptop/PC and Powerstrip software
3) Try to create a modeline that works for your TV
Please post your TV model number, and what the connection is between your PC and your TV.
Your TV manual will normally list the supported resolutions and frequencies for each type of input (VGA, HDMI etc). If you can, please list them (e.g. 1366x768 60Hz).
Even if you get the ATI card to work without driving the TV batty you may find (as I did) that weird stuff happens, like the LinuxMCE menus blinking on for 1/10 of a sec then vanishing.
The easiest way around this is to get an Nvidia 8500GT (Gigabyte fanless version) or 8600GT (Zotac fanless version). Plug it in and in your BIOS disable your ATI display chips on the motherboard.