It darkens the images and make it bad. This is one major thing that I dun like. Realised it can be disabled, I immediately disabled it.
The following 2 fixes I can reference for anyone that needs it:
Color correction for images:
gfx.color_management.mode = 0
Restart browser for it to take effect.
Closing first tab closes entire window:
browser.tabs.closeWindowWithLastTab = FALSE
Note that I only started using firefox from 3, so whatever may have happened with more experienced firefox users, please pardon me.
Edited by lyk13, June 30, 2009 - 12:03 AM.