This is good advice.
Originally Posted by ZombieBerry
Whenever I have an issue trying to install an update that the DM doesn't see, I close down all RIM related services (Task Manager), and then reboot my computer while it is connected to my BB.
9/10 usually works.
It may also help to ensure the vendor xml files are deleted from the, user (name) app data files in Win 7 under "Roaming" Research in Motion file