Unable to retain screen resolution on boot/reset

Question

Hello,
I have an external LCD connected to my mini, which has worked very well for the past few months. However, now the screen resolution that I use (1280x1024) is not applied on boot, and something along the lines of 640x480 is used (I can only judge this from the large size of the login prompt).
I can get the proper resolution by putting the system to sleep at the login screen. When I log in at the low resolution, my screen goes off to display 'resolution no supported' message. Again, I can bring back the proper resolution in this state by putting the system to sleep.
This situation is recent. The last major change before this problem, was upgrading to 10.5.4 form 10.5.3. Any help in resolving this annoying issue would be appreciated. Thanks.

Answer 1

Welcome to Apple Discussions, darthvinyll.
It sounds like possibly the preferences file(s) for displays has become corrupted on the mini. Probably the best thing to do at this point will be to trash the preferences file(s) associated with displays. Starting from the top level in the file system, meaning starting from the hard disk's icon within the Finder, in /Library/Preferences there should be a file labeled com.apple.windowserver.plist. Throw it in the trash. Also, for however many user accounts are on the mini, there should be files in /Users/name/Library/Preferences/ByHost that are named com.apple.windowserver.xxxxxxx.plist where xxxxxx is a random string of letters and numbers and where name is the name on the account. Throw all of those files in the trash as well, then restart the mini.
When OS X restarts and finds those files missing from their expected location, it will generate fresh copies with factory default values. That should give you a fresh start with the monitor. Good luck.