What Elijah said is true, but only in the fact that Google says this on their site. My experience has been that this has not penalized sites, and I believe it has helped many achieve better rankings despite googles posted "warning"
For example. go to
www.google.com and search for the terms (without quotes) "early morning show"
In this case, (and many others) this website has achieved a #6 rank...
In this case, the <div> tag is not technically hidden. There is just a style applied to the tag that results in it being hidden. *BIG* difference Elijah!!!
- if this is still a concern, try defining a class in your CSS that hides the <div> tag and call just that class, instead of including the style in-line.