Screen size is bigger than display size

jussi@jussi:~$ xrandr --verbose
Screen 0: minimum 320 x 200, current 1440 x 900, maximum 1680 x 1200
VGA-0 connected 1440x900+0+0 (0x53) normal (normal left inverted right) 474mm x 296mm
        Identifier: 0x4c
        Timestamp: 1466518361
        Subpixel: no subpixels
        Clones:
        CRTC: 0
        CRTCs: 0 1
        EDID_DATA:
                00ffffffffffff001e6d64565bcb0400
                061101036a2f1e78ead425a455499b27
                135054a76b80950f950081808140714f
                0101010101017c2e90a0601a1e403020
                3600da281100001a21399030621a2740
                68b03600da281100001c000000fd0038
                4b1c530f000a202020202020000000fc
                004c32323257000a20202020202000b6
        load_detection: 1 (0x00000001) range: (0,1)
  1680x1050 (0x4f) 119.0MHz -HSync +VSync
        h: width 1680 start 1728 end 1760 total 1840 skew 0 clock 64.7KHz
        v: height 1050 start 1053 end 1059 total 1080 clock 59.9Hz
  1680x1050 (0x50) 146.2MHz +HSync -VSync
        h: width 1680 start 1784 end 1960 total 2240 skew 0 clock 65.3KHz
        v: height 1050 start 1053 end 1059 total 1089 clock 60.0Hz
  1280x1024 (0x51) 135.0MHz +HSync +VSync
        h: width 1280 start 1296 end 1440 total 1688 skew 0 clock 80.0KHz
        v: height 1024 start 1025 end 1028 total 1066 clock 75.0Hz
  1280x1024 (0x52) 109.0MHz -HSync +VSync
        h: width 1280 start 1368 end 1496 total 1712 skew 0 clock 63.7KHz
        v: height 1024 start 1027 end 1034 total 1063 clock 59.9Hz
  1440x900 (0x53) 136.8MHz -HSync +VSync
        h: width 1440 start 1536 end 1688 total 1936 skew 0 clock 70.6KHz
        v: height 900 start 903 end 909 total 942 clock 75.0Hz
  1440x900 (0x54) 106.5MHz -HSync +VSync
        h: width 1440 start 1528 end 1672 total 1904 skew 0 clock 55.9KHz
        v: height 900 start 903 end 909 total 934 clock 59.9Hz
  1280x960 (0x55) 101.2MHz -HSync +VSync
        h: width 1280 start 1360 end 1488 total 1696 skew 0 clock 59.7KHz
        v: height 960 start 963 end 967 total 996 clock 59.9Hz
  1152x864 (0x56) 108.0MHz +HSync +VSync
        h: width 1152 start 1216 end 1344 total 1600 skew 0 clock 67.5KHz
        v: height 864 start 865 end 868 total 900 clock 75.0Hz
  1152x864 (0x57) 104.0MHz -HSync +VSync
        h: width 1152 start 1224 end 1344 total 1536 skew 0 clock 67.7KHz
        v: height 864 start 867 end 871 total 905 clock 74.8Hz
  1024x768 (0x58) 78.8MHz +HSync +VSync
        h: width 1024 start 1040 end 1136 total 1312 skew 0 clock 60.1KHz
        v: height 768 start 769 end 772 total 800 clock 75.1Hz
  1024x768 (0x59) 65.0MHz -HSync -VSync
        h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.4KHz
        v: height 768 start 771 end 777 total 806 clock 60.0Hz
  832x624 (0x5a) 57.3MHz -HSync -VSync
        h: width 832 start 864 end 928 total 1152 skew 0 clock 49.7KHz
        v: height 624 start 625 end 628 total 667 ...

Bug fixed with workaround Supplied by Radeon Maintainer on Xorg list.

(add modelines for monitor).

Modelines added:

Modeline "1680x1050_60.00" 146.25 1680 1784 1960 2240 1050 1053
1059 1089 -hsync +vsync
Modeline "1680x1050R" 119.00 1680 1728 1760 1840 1050 1053 1059
1080 +hsync -vsync