Monochrome photo looks blue in sRGB-aware browsers

Question

I have a scan of an old black & white photo. It comes into photoshop with an embedded "Epson gray gamma 2.2" profile. I then say Convert to Profile sRGB. This makes no visible difference to the image but now the IMAGE/MODE shows RGB color/8-bit per channel instead of grayscale. It looks ok.
Now I use SAVE AS (not SAVE FOR WEB) and save it as a JPG with the box ticked to get the sRGB profile embedded. I then put this JPG into an HTML page and browse to it using Safari and Firefox browsers. Both of these are colour management aware. (Firefox has gfx.color_management.mode=2 which means it will apply profiles if and only if they are embedded.)
And the problem is that both browsers show the image with a blue tinge:-
Left to right: Safari, Firefox, Photoshop.
Before anyone says "your monitor profile is wrong" please note I am displaying all three on the SAME monitor.
The blue tinge is confirmed by loading the screen capture into Photoshop and using the eyedropper: the left two have different R/G/B values with the B higher; the right one has identical R/G/B values.
If I SAVE the same image out of photoshop without an embedded profile (thus stopping the browsers from using colour management), all three look the same.
Question 1: Why does a colour aware browser give a blue tinge to monochrome sRGB?
Whilst playing with this I noticed a funny thing: if I drag the Photoshop image window (left click, hold down, drag) - to reposition it on the screen - the image temporarily goes blue in Photoshop, until I let go of the mouse. Whilst blue, it looks identical to the browser ones. I speculated that Photoshop thinks to itself, "he's moving the image, he may move it onto another monitor, I'll temporarily stop converting into the gamut of the monitor profile whilst he's doing this". However, that does not seem to be the answer because if I turn soft proofing on, and set the proof to my monitor profile, (thus paradoxically stopping Photoshop from converting into it) it does not go blue.
Question 2: Why does the colour of an image change in Photoshop as one drags the image window? What is Photoshop doing?

Answer 1

No difference here in any number of viewers / browsers with/without color management.
Are you absolutely sure you set your system to use sRGB for the monitor profile when you did the test I suggested above?
Did you reboot after having made the change?
Are you running any other software - e.g., an old version of Adobe Gamma or something - that might be affecting your color management landscape?  Anything in the video drivers claim to help manage color management at startup?
Might be time for a new video card, anyway.  Something tells me swapping that out and getting the system re-profiled will end up fixing the problem.
-Noel