I ran into this weird problem of not getting rid of the 5 px padding in the body of my webparts. Well it seems to be a known 'bug'. MS probably fixes it in the next release. There is a workaround to overcome the prblem. Took me some time to figure out what they had in mind.

Bug report:
http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=105167


WebPartChrome and WebPartZone derived classes you need.
http://msdn2.microsoft.com/en-us/library/system.web.ui.webcontrols.webparts.webpartchrome.aspx


download fixed classes:

http://www.overnight.nl/download/OvernightWebPartChromeAndZone.rar