Another problem I’ve found, which is already known by MS, but hasn’t been addressed, is that when a minimal panel size is set in a splitPanel, if the SplitterDistance is less that the minimal size, and exception is through.  This is fine, except the splitterDistance is set after the minimalPanelSize and the ClientSize, so the exception is thrown, even though the code generated by both the Designer and manually should work.

Follow the link for the work around:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=332395&SiteID=1