Eyedropper bug

Question

hi everyone,
it seems Photoshop's eyedropper or CMS has a problem. I have attached a sample .psd file so that everyone can reproduce the error.
Just open it and switch Layer1's blending mode from Screen to Linear Dodge. You will notice that as a result the gray pixels will visually get slightly brighter, but the eyedropper will show RGB=(38,38,38) in both cases! (you can measure anywhere in the image's center, for example the pixel (X=51,Y=35), that's the point where I measured for the screenshots below).
The point is: any pixel identified by Photoshop as RGB=(38,38,38) should ALWAYS look the same, not sometimes brighter and sometimes darker.
If you don't trust your eyes (which can fall pray to an optical illusion), just open my screenshots in any application with an eyedropper (even Windows Paint will do I guess) and compare the values for the gray area (just make sure the eyedropper's sample size is 1x1 (point sample)). The values will differ.
Or if you don't want to rely on my screenshots, just make your own.
To provide for additional measurement, I also used an on-screen color-picker utility named "ColorCop" which displays the screen pixel's actual RGB values at the current cursor position in real time. The recorded values are obviously the same as can be retrieved from the screenshots shown below, i.e. RGB=(42,42,42) for screenshot 1 and RGB=(43,43,43) for screenshot 2.
NOTE 1: The issue is unrelated to any eventual rounding errors resulting from the blending modes and multiple layers. To prove this, you can flatten the image (menu: layer >> flatten image). Still the same problem.
NOTE 2: For those of you familiar with colour management, the actual values retrieved from your screenshots depend on the color profile currently associated with your monitor. This accounts for the differences between RGB=(38,38,38) and the values in the screenshots (in my case 42,42,42 and 43,43,43). Your values will obviously differ. I also noted that if you choose sRGB as your monitor profile, the error cannot be reproduced.
settings:
colour picker sample size: 1x1
measured document pixel: X=51, Y=35
measured screen pixel: X=602, Y=510
Adobe Photoshop: CS3
document colour space: (irrelevant, sRGB)
.psd document in question: attached
screenshot 1 (RGB=38,38,38 shown as darker gray):
(click to enlarge!) :
screenshot 2 (RGB=38,38,38 shown as lighter gray):

Answer 1

still looks like a simple rounding error to me, when looking in CMYK you get 71/65/64/70 for screen and 71/65/64/69 for Linear Dodge