I just reverted my working space back to North American Standard 2 and fiddles a bit with my saving options (disable compensation etc. etc.)
Is it fixed? Is it a possibility that it may be a problem with your settings on 'Save For Web & Devices'?
Nope it is still a problem, and it doesn't seem to be a saving issue, photoshop itself seems to lighten every image i open into it or create in it.
Sorry, I don't know photoshop, but...
Have you tried fiddling with the "monitor gamma" knobs of photoshop, if there are any?
Image editing programs sometimes use there own gamma settings, but most of the programs that just display images (like a web browser) don't apply any gamma correction... so turning your photoshop gamma to 1.0 should be okay if you want to make pictures that will be mainly displayed in a web browser...