From the ATi FAQ: Computer monitor loses sync when TV OUT feature is enabled Some monitors may lose sync when TV OUT is enabled. Generally, one of the following resolutions is affected: 320x240 640x480 800x600 Other monitors may power down, display an error such as "frequency out of range", flicker badly, flash on and off, or snap between different screen sizes. The TV display looks fine. This symptom may occur with VGA, fixed frequency or multi-mode monitors, including: 31.5kHz standard VGA-only monitors 31.5/35.5kHz dual mode monitors 31.5/35.5/48.0kHz multi-mode monitors This issue occurs because enabling TV OUT (e.g. by booting with a TV attached) changes the horizontal frequencies output by the ATI graphics controller, as shown below: ........................ The default horizontal frequency must be altered in order to create the proper display on the television. Since ATI's TV OUT technology sends exactly the SAME horizontal and vertical frequencies to both the TV and the computer monitor, any monitor which does NOT support the altered horizontal frequency will lose sync. The TV OUT feature is working as designed, in order to provide a proper display on the Television set. If the PC monitor will not sync while TV output is enabled try one of the following: Detach or turn off the computer monitor when using TV OUT Use a multi-sync monitor which DOES support the required frequencies Disable the TV OUT feature ___________________________________________ I'm aware of, and have read this on several occasions. However, it does not address WHY the CAT 3.4 drivers work just fine when I reboot my computer with TV-OUT enabled, but NEITHER CAT 3.5 or 3.6 do. My monitor is capable of a wide-range of frequencies and should pose no problem when the computer is booted with TV-OUT enabled. It DOES work just fine using CAT 3.4....why not the newer ones?