I hope you use the latest liveCD (version 0.3.4-8). You can try the previous one, 0.3.4-7.
Did this happen with the default (first) boot option? (autoconfig)
If it is so, you can try the other boot options in the initial boot menu. Especially the option "old config method" (4rth line in the 0.3.4-8), and "Force VESA driver".
The message "Input signal out of range" comes from the monitor itself and means that it can synchronize with the graphics card signal.
You can try to press "control+alt+backspace", and then you would come back to a text terminal screen. There, you can enter the command "Forcevideo" (attention to the capital F: case sensitive).
You will be asked for a graphics driver to use, from a long list. There are options for ati and radeon.
Next, you enter the resolution to use, or press enter for default choice. In that case, the choice is the maximum supported, but you can enter a "safer" choice, like 800x600 or 1024x768.
In avy case, you can reboot the computer from the text screen with the command "reboot".
*** It is highly recommended to backup any important files before doing resize/move operations. ***