Many Thanks to headrift and thorkelljar for their help and support. Unfortunately every thing I tried "can not open Monitor" or something to that effect. Thinking out side the square. I just plugged in a monitor that had a higher resolution than my monitor (ie a projector) i was then was able to change the resolution from the desktop. Again thanks.
Did your monitor work fine until you logged into the system, I mean would it work fine until after you entered your passwd and as it started your session the monitor went blank? If this is the case, your solution was the easiest. The problem is/was not with your xserver xorg.conf it was with the Window Manager. Unless you know what and where the config file is for the monitor setting kept by your Window Manager the windows manager would have continued to default to that setting. I had the same problem awhile back, I changed the setting in Gnome that went outside the bound of my monitor. I spent several hours trying to find the window manager config file but ended up doing the same thing as you did to solve the problem.
I have had this happen in Windows also, although with 98 and xp the default is to test the monitor for x-many seconds and fall back to the previous setting unless prompted by the user. So don't get frustrated with linux as this can happen with any OS.