Comment 20 for bug 201491

I've got a similar issue, but not sure if it's exactly the same cause. My Xorg.0.log file starts with the right idea and changes its mind at the end.

Initially it looks OK with these log lines showing correct values:
(II) intel(0): Max Image Size [cm]: horiz.: 38 vert.: 30
(II) intel(0): clock: 108.0 MHz Image Size: 376 x 301 mm
(**) intel(0): Display dimensions: (380, 300) mm
(**) intel(0): DPI set to (85, 86)

Then, towards the end it changes it's mind, only the one line I can see:
(II) intel(0): Setting screen physical size to 338 x 270

(I'll attach the full file after this comment). This gives you about 96x96 dpi I think, which is what xdpyinfo reports.

I use "xrandr -dpi 85" to get around the problem (fixes document-viewer and GIMP), and change the DPI settings in gnome (fixes window fonts).