This article explains the reasons for the 10MB size limit on uploads to sitekit.

• The size of files that can be uploaded into the file library via the Sitekit CMS web interface is limited to  ~10 Mbytes.
• The size limit is set in web.config via <httpRuntime maxRequestLength="10240" />
• Anything exceeding this limit throws a sorry error in global.asax stating "System.Web.HttpException: Maximum request length exceeded. at System.Web.HttpRequest.GetEntireRawContent".
• Microsoft recommends having a limit of between 10 and 20 Mbytes to prevent a Denial Of Service attack -  though their default value( if not explicitally set in web.config) is just 4 Mbytes. They state that a file has to be fully loaded into the servers physical memory by IIS before it is uploaded and that any file taking up more than 20% of this physical memory will likely cause IIS to recycle. http://support.microsoft.com/default.aspx?scid=kb;EN-US;295626