My LG Flatron L1750SQ displays "OUT OF RANGE 36.8 khz / 82 Hz" for about 10 seconds before I see the kde loading screen.

It has done this since I installed Kubuntu Dapper even though i have ran:
"sudo dpkg-reconfigure xserver-org" and set my monitor's horizontal and vertical scan frequency from an information booklet on the web. (horizontal scan frequency 30-83kHz, vertical scan frequency 56-75 Hz).

Try deleting the resolution(s) that you don't want if your xorg.conf. ie so you just have something similar to the following in your 'screen' section in xorg.conf. It might be trying to load higher resolutions which is not supported, then realising it is not supported, and trying the next one, then the next one. Make it easier and say what you want.

Section "Screen"
Identifier "Screen0"
Device "Videocard0"
Monitor "Monitor0"
DefaultDepth 24
Option "metamodes" "CRT: 1680x1050 +0+0"
SubSection "Display"
Depth 24
Modes "1680x1050"
EndSubSection
EndSection