First of all thanks a lot for your help....
Eric, I didn't intend to be lazy and waste your time by leaving you there comparing while knowing what's exactly wrong here....as part of my problem is that I didn't know what' exactly wrong here, is it a background image...is it something else?!
If the background image is the problem then why it is visible and working normally on Chrome while not visible on IE and Firefox 3.6?!
As of re-saving the image, re-uploading...etc I've tried all those steps nothing worked....I've even tried to re-build the theme from scratch again and it didn't work
So any suggestions?
Ryan, how I can know if a CSS is valid or invalid?
Thanks in advance for your time and efforts