I'm installing SharePoint 2010 on a Windows Vista x64 SP1 and is getting the 'allowInsecureTransport' error on the create sample data pass of the configuration wizard. Unfortunately the fix won't install and I'm getting the 'The update does not apply to your system'. Maybe there's missing an fix for Vista x64?
However I managed to complete the wizard by removing the two allowInsecureTransport="true" sentences (remember not to remove the closing tag :)) from the client.config found at "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\WebClients\Profile" thanks to a tip from http://www.mcpblog.net/Lists/Posts/Post.aspx?List=8f2497f6%2De77b%2D4e70%2D8400%2De020b292165c&ID=61. Note that you don't have to uninstall SharePoint, only remove the two lines.