Confirm Installation:
* There must be a directory in the root named .rockbox: X:\.rockbox (note the period)
* There must be a file in that directory named rockbox.gigabeat: X:\.rockbox\rockbox.gigabeat (note the period). The older location of root still works as well: X:\rockbox.gigabeat, but when you update using rockbox.zip only the newer location of X:\.rockbox\rockbox.gigabeat is updated.
This is what I was talking about