Color Changing background

I just noticed that remote file listing panels semi-randomly change their background color when i switch to local listing and then back

See darker shaded background below file listing on the left and white background on the right http://mxxcon.trvx.com/dark.png
now after switch either side to local listing a few times now see that left panel now has totally white background but right panel is now darker shaded http://mxxcon.trvx.com/flipped_dark.png

Also notice cut off double line between Date and Attrib columns.