It sounds like the font color of your profile information is the same as your background, making it blend in and look invisible.

To change your profile font color, you'll need to go into your Look and Feel:

Look for the section titled "Left Side Modules" - this controls all the modules on the side including your Profile Module. Currently there isn't an option where you can just change your profile colors.

Here you can change the border color - rectangle surrounding your profile, the title bar color (the part that says Subscriptions, My blogrings, etc.), Interior - color inside the modules, Title Text - color of the words Subscriptions, My blogrings, etc, and Module Text - this is the color of the words you put in your modules. This includes your Expertise, Interests, Name, etc.

Please note that your module text should be a different color than your background - or you may not be able to see the text, giving the appearance that it is missing.

Please note that if you have a skin, the skin will override the Look and Feel settings. If you are using a skin, in order to fix your profile colors - you'll have to fix your skin directly.