Built-in gallery and XHTML validation

I rarely use the functionality of gallery. But recently I found that it generate a style tag just before the gallery! As I am using XHTML strict, style tag is only allowed in the head section instead of body!

You may see the current state through this page: http://main.peterwongpp.com/post/2709
which has a gallery in the post and so creates such kind of validating error.

Please could any one help me or at least give me some hints about the built-in gallery?