A small report about screen resolution:
 1.     1024x768     95     39.09%
 2.     1280x1024     76     31.28%
 3.     1600x1200     13     5.35%
 4.     1280x800     13     5.35%
 5.     1400x1050     13     5.35%
 6.     1152x864     12     4.94%
 7.     800x600     7     2.88%
 8.     1680x1050     6     2.47%
 9.     1440x900     4     1.65%
10.     1920x1200     3     1.23%
There is about 42% for 1024x768 & 800x600, while other resolution (usually larger resolution) is about 58%!
And the above report is from website http://j2s.sourceforge.net/ Java2Script, which is oriented for global UI designers.

The following report is from a website which is oriented for Chinese normal user (for ebooks resources):
 1.     1024x768     497     77.90%
 2.     800x600     80     12.54%
 3.     1280x1024     28     4.39%
 4.     1280x800     14     2.19%
 5.     1280x768     4     0.63%
 6.     1024x1536     4     0.63%
 7.     1152x864     4     0.63%
 8.     1280x960     3     0.47%
 9.     960x600     1     0.16%
10.     1920x1200     1     0.16%
90% of the users are using 1024x768 or 800x600. Other resolutions ocuppies the minority 10%.

Then, what resolution is your screen? And what resolution are you  designing for?