When posting images for the web to you do you make some post processing changes after you convert to sRGB? I notice that my images that I have posted always seem a bit flat compared to what I see in Pro Photo before exporting to JPEG. Also does it make a difference if you send your image to LULA vs your personal personal web host? After I get my images ready for printing the last thing I want to do is fiddle with them for the Web.
Except for highly saturated colours beyond the sRGB gamut, all colours should look identical in ProPhoto RGB and sRGB. If they don't, that normally means a colour management problem.
Is your monitor calibrated and profiled with a hardware device - Spyder, Colormunki etc? If so, is the profile OK? And what browser do you use? Firefox, Safari and Chrome (latest version) are colour managed, IE - even IE10 - is not.
But you shouldn't have to alter jpegs after exporting from your editor, unless there's a colour mangement problem.
