I was having the same problem - CS3 Contribute seems to float the div content so it is visible for editing but CS5 Contribute hides the hidden part. I found the fix for this for me at least was the "Element view" by right clicking the div and setting it to "Full" it then displays all the div content. Regarding the content having the same colour as the background colour I suppose you have to select the content or text and it should be visible?
North America
Europe, Middle East and Africa
Asia Pacific