For two long rainy days I worked on this. I loaded and deleted my certs and profiles so many times I had the instructions in the "iPhone Developer Program Standard Program Portal User Guide for OS X iPhone 2.0 " memorized.
These are a few of the fine details that finally got my Hello World app to load on my iPhone.
1. On your Mac's Keychain Access Program, under the login's Keys delete all the keys with duplicate names these are created while you are attempting to get your iPhone Developer Cert., profiles, etc to work. Only keep the key with the caret with the iPhone Developer sub category. Double click on this Key and set "Access Control" to "Allow all bla bla bla....."
2. On your Mac's Keychain Access Program, double click the login's 'My Certificates' iPhone Developer and under Trust set to "System Defaults"
3. In Xcode edit the "Bundle identifier" key in the info.plist of your application to read 123456.com.yourcompany.${PRODUCT_NAME:identifier} where 123456 is the Apple Id of your Provisioning Profile you created in
http://developer.apple.com/iphone/manage/provisioningprofiles/index.action, it should be a string with few numbers and letters with an * at the end. Substitute that string for the 123456. Remember this only works if, when you created your Apple ID you gave it a name and entered "*" for the App ID(Bundle Seed ....)
4. Then in Xcode under the Build tag of your applications "Project info" set the following:
-- Under "Code Signing identity" set the subcategory "Device = iPhone OS 2.0" -> "iPhone Developer:" to the same name in the "Keychain Access Program" of your iPhone Developer Key (mentioned my step 1 of this madness).
-- Set "Code Signing Provisioning Profile" to "Default Provisioning Profile for Code Signing Identity" and the subcategory "Any iPhone OS Device" to the same "Default Provisioning Profile for Code Signing Identity".
Success